Chapter 31: Abdominal Pain

General Considerations

Abdominal pain is the chief complaint for 5–10% of patients presenting to emergency departments and one of the top 10 complaints in the office. Because of the wide differential diagnoses, accurate diagnosis can be difficult. Detailed history, thorough physical examination, and often, diagnostic testing, are necessary.

Clinical Findings

A. History

History is the most important component of evaluating abdominal pain. Effective communication is necessary for a thorough, accurate history. Enough time should be allowed for open-ended history using the method “engage, empathize, educate, enlist.”

1. Onset

Determining onset of pain can help determine the cause of abdominal pain as well as the need for emergent referral. Abdominal pain is categorized as acute, subacute, or chronic. Symptoms lasting more than 3 months are considered chronic. Acute pain is often associated with peritoneal irritation, such as appendicitis, and abdominal organ rupture and may require emergency management and consultation with a surgeon. Many patients present to the office with more gradual onset or chronic abdominal pain (Table 31-1).

2. Quality of pain

A patient’s description of the quality of the pain provides clues to etiology. Pain can be sharp, stabbing, burning, dull, gnawing, colicky, crampy, gassy, focal, migrating, or radiating. Pressure like pain (“there’s an elephant sitting on me”) suggests cardiac ischemia. Focal symptoms help determine location and diagnosis.

3. Location

Location and radiation of pain are important. The abdomen is separated into four quadrants—right upper (RUQ), left upper (LUQ), right lower (RLQ), and left lower (LLQ)—or as midepigastric or suprapubic. Some causes of abdominal pain have classic patterns of location and radiation. Pain from the lower esophagus may be referred higher in the chest and confused with pain associated with cardiac conditions.

4. Frequency and timing

Frequency and pattern of pain are particularly useful in identifying the cause of chronic pain. Symptoms may be associated with eating, types of food, defecation, body position, or movement. Peritoneal irritation may be eased by lack of movement. Visceral pain may trigger a patient to move more to try to find a more comfortable position. Pain caused by colonic pathology may be relieved by defecation.

5. Other diagnostic clues and symptoms

Physicians should determine whether other symptoms are present such as nausea, vomiting, diarrhea, constipation melena, mucus, or hematochezia. Fever and chills suggest an infectious etiology. Feculent emesis correlates with bowel obstruction. The presence of blood or melena in the stool requires evaluation for gastrointestinal (GI) bleeding. A patient’s age may be a factor in both cause and perception of pain. The elderly may not present with classic symptoms of serious conditions and complain of vague or mild pain because of a 10–20% reduction in pain perception for each decade of age over 60 years. Emotional stress can trigger symptoms of functional bowel disease. Organic diseases also may be exacerbated by emotional stress.

Past medical history provides important clues to the etiology of pain. Previous abdominal surgery increases the risk for bowel obstruction secondary to adhesions, strangulation, or hernia. Patients with cardiovascular diseases are at greater risk for bowel infarction. Tobacco, alcohol, or medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with increased incidence of gastroesophageal reflux disease (GERD) and peptic ulcer disease (PUD). Alcohol abuse is a common cause of pancreatitis. Multiparity, obesity, and diabetes mellitus increase risk of gallbladder disease. Tubal ligation or pelvic inflammatory disease (PID) history indicate a greater risk for an ectopic pregnancy.

Medication history should include use of prescription and over-the-counter (OTC) medications and herbal supplements. Aspirin and other platelet aggregation inhibitors, steroids and nonsteroidal anti-inflammatory drugs (NSAIDs), and antidepressants increase the risk of gastrointestinal bleeding. Antibiotics can cause nausea, diarrhea, or both.

B. Physical Examination

1. Inspection

Position the patient supine with knees slightly bent. Inspect for distention, discoloration, scars, and striae. Distention suggests ascites, obstruction, or other masses. Discoloration from bruising associated with hemoperitoneum is found in the central portion of the abdomen, especially following abdominal trauma. The location of scars helps clarify and confirm past history. Striae suggest rapid growth of the abdomen. New striae or those related to endocrine abnormalities tend to be purplish or dark pink. Striae may appear as darkening of the skin in darker-skinned persons. The abdomen should be inspected for hernias with the patient in an upright position.

2. Auscultation

Auscultation is performed prior to palpation. Bowel sounds may be normal, hypoactive, hyperactive, or high-pitched. Hypoactive or hyperactive bowel sounds can be present with partial bowel obstruction, or ileus. Bruits over the aorta, renal arteries, and femoral arteries suggest aneurysms. Gentle palpation while auscultating decreases the likelihood that a patient will guard, embellish, or magnify symptoms.

3. Palpation

Palpation of the abdomen begins with light touch away from the area of greatest pain. Assess for rigidity, tenderness, masses, and organ size. Increased rigidity may indicate an acute abdomen and need for emergent intervention. A Murphy sign is the sudden cessation of a patient’s inspiratory effort during deep palpation of the RUQ and suggests acute cholecystitis.

Pain from visceral organs may radiate because of shared nerve innervation. Pain from pancreatitis often radiates to the back. Abdominal pain radiating to the left shoulder (Kehr sign) indicates splenic rupture, renal calculi, or ectopic pregnancy. Radiation of pain may be caused by inflammation of surrounding tissues.

The iliopsoas muscle test, performed by having the patient flex the right hip while lying supine and applying pressure to the leg, can be used to evaluate the deep muscles of the abdomen. Inflammation of the psoas muscle may indicate inflammation of nearby structures as seen with appendicitis or retroperitoneal dissection.

Rebound tenderness indicates peritoneal irritation and can occur with gastrointestinal perforation or non-GI sources such as a ruptured ovarian cyst and PID. Peritoneal irritation is often associated with guarding. Voluntary guarding occurs when a patient anticipates the pain. Patients who close their eyes as the examiner approaches (“closed-eye sign”) are more likely to have underlying psychosocial factors contributing to pain. Involuntary guarding is caused by flexion of the abdominal wall muscle as the body attempts to protect internal organs. The Carnett test, performed by having the patient flex the abdominal wall as the point of greatest tenderness is palpated, may help differentiate visceral pain from abdominal wall or psychogenic pain. Pain less severe with palpation of the flexed abdomen wall has a higher probability of being visceral than pain from abdominal wall pathology or nonorganic causes.

Two approaches may help examine a ticklish patient: use of a stethoscope for light palpation by curling fingers past the edge of the stethoscope to create a less sensitive touch; and placement of hands over the patient’s hand to palpate.

Evaluate liver and spleen by having the patient take a deep breath and exhale while palpating the organ’s border. The normal liver span at the midclavicular line is 6–12 cm depending on the height and gender of the patient. Assessing the midsternal liver size can be helpful. The normal span is 4–8 cm. A span of >8 cm is considered enlarged. The tip of the spleen may not be palpable.

Examine for masses that may be seen with colon cancer, kidney abnormalities, and non-GI tumors. A palpated mass should be examined for location, size, shape, consistency, pulsations, mobility, and movement with respiration.

4. Percussion

Percussion can help determine the size of organs and other abdominal pathology. A change in the character of the sound indicates a solid organ. The examiner should percuss both liver edges. The upper border usually sits at the fifth to seventh intercostal space. Inferior displacement suggests emphysema or other pulmonary diseases. The span of the spleen is evaluated in the left midaxillary line and usually extends from the sixth to the tenth ribs. The scratch test is another form of percussion. It is performed by placing the stethoscope over the liver and gently scratching the surface of the skin beginning above the upper border of the liver and progressing to below the lower border of the liver. The quality of the sound changes as the examiner’s scratch travels from the lung field to liver and abdomen. Changes in sound help identify the liver borders.

Increased tympany should be present over the stomach in the area of the left lower border of the rib cage and left epigastrium because of the gastric air bubble. Increased tympany throughout the rest of the abdomen suggests dilation or perforation of the bowel. Dullness can be stationary, as with solid masses, or shifting, as with mobile fluid. Shifting dullness generally is present with significant ascites.

5. Pelvic exam

A pelvic examination may be indicated in female patients with abdominal pain.

C. Laboratory Findings

Testing should include complete blood cell count (CBC), electrolytes, blood urea nitrogen (BUN), creatinine, and glucose. Alkaline phosphatase and liver function tests can be helpful. Normal hemoglobin and hematocrit in the setting of acute rapid blood loss can be misleading and should be rechecked after the patient is fluid-resuscitated. Anemia, especially in those aged >50 years, should prompt iron studies, including ferritin level. Hypothyroidism in the elderly may present with vague abdominal pain, so a thyroid-stimulating hormone level may be helpful.

Right upper quadrant pain should be evaluated with bilirubin, lipase, amylase, trypsin, and liver function tests. Hepatitis panels may be useful. Amylase is elevated in pancreatitis and many other abdominal problems. Therefore, lipase and trypsin level are more specific for pancreatitis.

Stool studies may be indicated when the patient presents with abdominal pain and diarrhea. Stool testing should be done for dehydration, for blood in the stool, or with immunocompromised patients. Stool white blood cell count (WBC), hemoccult testing, ova and parasite, culture for enteric pathogens, and Clostridium difficile toxin level, are indicated for chronic or bloody diarrhea. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) should be checked if inflammatory bowel disease is suspected, especially if WBCs are found in stool. Intermittent symptoms suggesting celiac disease may warrant laboratory tests for antiendomysial antibody.

Women of childbearing age should have a pregnancy test regardless of history of tubal ligation. Patients with lower abdominal pain may need a urinalysis (UA), although other intraabdominal problems can cause changes in UA similar to urinary tract infection. Consider vaginal testing for sexually transmitted infections, including gonorrhea and Chlamydia. Cardiac studies should be considered for at-risk patients. Studies including magnesium, calcium, and vitamin D levels may be indicated for nonspecific complaints.

D. Imaging Studies

Plain films of the abdomen are low-cost, widely available, and safe initial diagnostic tests. Upright and lateral decubitus films of the abdomen can show dilated small bowel loops (suggestive of obstruction), free air (perforated organ), mass (tumor or other obstructing cause), or stones (biliary or renal). Small bowel follow-through may show ulcer or mass. Barium enema can be useful for evaluation of constipation.

Computerized tomography (CT) of the abdomen and pelvis is the test of choice for many acute and nonacute causes of abdominal pain. Protocols for specific problems limit radiation exposure while providing accurate information. Spiral CT for appendicitis and renal calculus has been shown to be fast, safe, effective, and cost-effective. Other problems well visualized by CT scan include diverticulitis, bowel obstruction, pancreatitis, abdominal aortic aneurysm, pneumoperitoneum, soft-tissue tumors, and radiopaque renal and biliary stones.

Ultrasonography (US) is the most reliable imaging study for the biliary system and pelvic organs, the test of choice for most RUQ pain, and can identify hernias. The lack of contrast material and radiation makes it useful for pregnant patients. Children may tolerate US better than CT scan because the exam time is shorter and there is less need to remain completely still. The accuracy of US is more operator-dependent and is limited by obesity.

Direct visualization of the GI tract is often needed for chronic pain. Upper endoscopy is used for evaluation of dyspepsia, ulcers, and other upper gastric abnormalities. This imaging modality allows for visualization, biopsy of mucosal lesions, and treatment of bleeding. Colonoscopy or sigmoidoscopy is indicated for most patients aged >50 years or with other risk factors for cancer. Direct visualization of the colonic mucosa can help in diagnosis of diverticulosis, cancer, diarrhea, and inflammatory bowel disease.

Other modalities available for imaging of the abdomen include magnetic resonance imaging (MRI). Imaging modalities for urinary system problems are discussed elsewhere.

General Considerations

The term dyspepsia was first used in the early eighteenth century to describe a person’s ill humor, indigestion, or disgruntlement. The term now describes a set of symptoms encompassing different diseases and the etiologies associated with them. Chronic or recurrent discomfort centered in the upper abdomen commonly describes dyspepsia and can be associated with heartburn, belching, bloating, nausea, or vomiting. Common etiologies include PUD and GERD. Rare causes include gastric and pancreatic cancers.

Dyspepsia is reported to affect 40% of the world’s adult population and accounts for 2–3% of all visits to primary care providers. Only ~10% of affected adults seek medical advice. No specific etiology is found for 50–60% of patients presenting with epigastric pain. Nonulcer dyspepsia or functional dyspepsia applies to patients with symptoms lasting >3 months without a clear etiology. Other infrequent etiologies include gastric, esophageal, and pancreatic cancer; biliary tract disease; gastroparesis; pancreatitis; carbohydrate malabsorption; medication-induced symptoms; hepatoma; intestinal parasites, non-GI diseases such as sarcoidosis, diabetes, thyroid, and parathyroid conditions; and metabolic disturbances such as hypercalcemia and hyperkalemia. Studies have shown that symptoms and degree of symptoms do not correlate with findings on endoscopy.

Dyspepsia is caused by PUD in 15–25% and GERD in 5–15% of cases. Abdominal exam may be unremarkable unless an ulcer perforates, causing signs of peritonitis. Treatment for dyspepsia depends on the etiology and is discussed in sections on PUD, GERD, and nonulcer dyspepsia.

Peptic Ulcer Disease

General Considerations

The four major causes of ulcers are Helicobacter pylori–induced ulcers, NSAIDs, acid hypersecretory conditions, and idiopathic ulcers. Clear evidence supports eradication of H. pylori in patients with documented ulcers. Since the early 1990s, the association of H. pylori with peptic ulcers has decreased from 90% to as low as 15–20% in some countries. This decrease is related to increased treatment of H. pylori infections, which are commonly associated with low income, low educational levels, and overcrowded living conditions. African Americans and Hispanics have about a one-third higher rate of infection than white Americans. In the United States, 40% of adults are infected with H. pylori by the age of 50, compared with only 5% of children aged 6–12 years. In developing countries, children commonly are infected at a younger age and there is a higher incidence of infection in the entire population.

Pathogenesis

In the past, infection with H. pylori was the leading cause of peptic ulcers and NSAID use was second. Now NSAID use and idiopathic ulcers are the most common causes. In the United States, one in seven individuals uses NSAIDs. Of long-term NSAID users undergoing upper endoscopy, 5–20% are found to have an ulcer. Risk factors for developing ulcers due to NSAID use are a personal history of ulcer, age >65 years, current steroid use, use of anticoagulants, history of cardiovascular disease, and impairment of another major organ. NSAIDs are prescribed to nearly 40% of all persons aged >65 years. Elderly patients treated with a course of with NSAIDs have a 1–8% chance of being hospitalized within the first year of therapy for GI complications. Patients who are H. pylori–positive and take NSAIDs have a higher risk of complications.

Prevention

Eradication of H. pylori infection before starting a course of treatment with NSAIDs reduces the risk of developing an ulcer early in the treatment, particularly with duodenal ulcers. Treatment with PPI is standard for secondary prevention of gastoduodenal ulcers.

Clinical Findings

Factors suggesting PUD include gnawing pain with the sensation of hunger, prior personal or family history of ulcers, tobacco use, and a report of melena. The most accurate diagnostic test is esophagogastroduodenoscopy (EGD). It allows both visualization and biopsy of an ulcer as well as testing for H. pylori. Good evidence supports a “test and treat” approach. The most cost-effective noninvasive test is the monoclonal stool antigen test. Breath urea testing is noninvasive but more expensive and may not be as accurate. Serology testing is used mainly for research or surveillance but may be indicated for actively bleeding ulcers, complicating performance of an EGD.

Complications

Elderly patients (aged ≥80 years) with ulcers who take aspirin or have H. pylori infection have a much higher incidence of complications. A hypersecretory condition, such as Zollinger-Ellison syndrome, caused by a gastrin-producing tumor should be suspected in patients with multiple ulcers. The incidence of GI bleeding from the upper GI tract has decreased. This may be related to the increased treatment of H. pylori.

Treatment

Treatment of PUD requires initial eradication of H. pylori if present, reducing or discontinuing NSAID use, and treatment with a proton pump inhibitor (PPI). The Food and Drug Administration (FDA)-approved regimens for treatment of H. pylori include concomitant or sequential treatment with two or three antibiotics plus a PPI. Refer to Centers for Disease Control and Prevention (CDC) and local guidelines. Treatment of H. pylori facilitates healing of ulcers and decreases rate of recurrence in the first year from 75% to 10%. Increased effectiveness of medical treatment for PUD has decreased the need for surgical intervention. Surgery, when performed, is commonly laparoscopic.

Gastroesophageal Reflux Disease

Clinical Findings

Heartburn is the single most common symptom of GERD. Ten percent of the US population experience heartburn at least once a day, and almost 50% experience symptoms once a month. Other common symptoms include regurgitation, belching, and dysphagia. GERD can be associated with extraesophageal symptoms and conditions. Pulmonary conditions include asthma, chronic bronchitis, aspiration pneumonia, sleep apnea, atelectasis, and interstitial pulmonary fibrosis. Ear, nose, and throat manifestations of GERD include chronic cough, sore throat, hoarseness, halitosis, enamel erosion, subglottic stenosis, vocal cord inflammation, granuloma, and, possibly, cancer. Noncardiac chest pain, chronic hiccups, and nausea may be associated with GERD. Changes in body position such as lying down or bending forward may exacerbate symptoms of GERD.

The esophagus has three mechanisms in place to prevent mucosal injury. The lower esophageal sphincter (LES) creates a barrier to acid reflux. Peristalsis, gravity, and saliva provide acid clearance mechanisms. Epithelial cells provide resistance.

Diagnosis is based on the medical history and response to treatment with H₂-receptor antagonists, prokinetic agents, or PPIs. Symptomatic improvement following treatment can indicate GERD. Diagnosis may be suggested by use of symptom questionnaires, catheter and wireless pH-metry, and impedance-pH monitoring. Upper endoscopy fails to reveal 36–50% of patients diagnosed via esophageal pH monitoring. Patients with typical symptoms and response to PPIs do not need further evaluation. Endoscopy should be performed if alarming symptoms are present, such as bleeding, weight loss, dysphagia, or persistence of symptoms after treatment with a PPI, especially in elderly patients. Complications of GERD include Barrett esophagus, esophageal strictures, ulceration, hemorrhage, and rarely, perforation. Barrett esophagus is found in 8–20% of patients who undergo upper endoscopy for GERD.

Treatment

Lifestyle modifications with the greatest impact on reducing symptoms of GERD include weight loss in overweight and obese patients, cessation of smoking, moderation of alcohol, consumption, and reduction of dietary fat intake. Limiting foods that decrease LES pressure (chocolate), stimulate acid secretion (coffee, tea, and cola beverages), or produce symptoms by their acidity (orange or tomato juice) may be helpful. Elevating the head of the bed by 6 inches, avoiding bedtime snacks, and reducing meal size, particularly in the evening, may help ameliorate symptoms.

Medication treatment options decrease acid or help with other defense mechanisms. Commonly used over-the-counter (OTC) medications include antacids, simethicone, and H₂-blockers. Prescription medications include prescription-strength H₂-blockers, PPIs, prokinetic agents, bethanechol, and sucralfate. Agents that irritate the mucosa (eg, aspirin and NSAIDs) should be avoided. Other agents to avoid include α-adrenergic antagonists, anticholinergics, β-adrenergic agonists, calcium channel blockers, diazepam, narcotics, progesterone, and theophylline.

If a patient’s symptoms resolve or significantly improve with treatment, no further evaluation is needed. If the symptoms do not improve with an 8-week course of PPIs, endoscopy is indicated. Risks of developing long-term complications remain even when symptoms improve. Patients with Barrett esophagus need close monitoring because of a 50–100-fold increased risk of developing esophageal cancer.

Nonulcer Dyspepsia

General Considerations

Nonulcer dyspepsia, also called idiopathic or functional dyspepsia, is defined as persistent or recurrent dyspepsia without evidence of organic disease present for 3 months with onset more than 6 months prior to diagnosis, not relieved by defecation, and not associated with the onset of change in stool frequency or form. Nonulcer dyspepsia is divided into at least two distinct subgroups: postprandial distress syndrome, which features postprandial fullness and early satiety; and epigastric pain syndrome, which features more constant and less meal-related symptoms.

Nonerosive reflux disease (NERD) is defined as having typical symptoms of GERD but absence of visible esophageal mucosal injury when EGD is performed. Nonulcer dyspepsia and NERD may represent different aspects of the same disease entity.

Pathogenesis

The pathophysiology of nonulcer dyspepsia is not entirely clear and is probably multifactorial. Suggested causes include changes in gastric physiology, nociception, motor dysfunction, central nervous system (CNS) dysfunction, and psychological and environmental factors. H. pylori and its effects on nonulcer dyspepsia are highly controversial. A percentage of patients with nonulcer dyspepsia and H. pylori have significant improvement in their symptoms after using eradication therapy, yet improvement cannot be guaranteed. Approximately 50% of patients with nonulcer dyspepsia are H. pylori–positive.

Clinical Findings

Nonulcer dyspepsia is diagnosed by excluding other causes of dyspepsia. Endoscopy is negative with nonulcer dyspepsia and NERD. A therapeutic trial of PPIs and/or “test and treat” for H. pylori are common practices supported in the literature. Cost-effectiveness data indicate that testing and treating patients for H. pylori decreases the number of EGDs performed by about one-third.

Treatment

Management of nonulcer dyspepsia is multifactorial. Early diagnosis and explanation of the relevant physiology is helpful to patients. Physicians should avoid excessive investigation, although patients with previous diagnosis of nonulcer dyspepsia should be investigated whenever alarm symptoms are present or a new objective symptom arises. Alarm symptoms are highlighted by the mnemonic VBAD: vomiting, evidence of bleeding or anemia, presence of abdominal mass or weight loss, and dysphagia. The prevalence of H. pylori in the community may factor into the decision to “test and treat” or perform other investigations. Physicians should determine why the patient with chronic symptoms presented at this particular time.

Psychosocial factors exacerbate symptoms. Physicians should address these issues and offer counseling. Postevaluation reassurance is a mainstay of management. Patients should be told to avoid foods or substances that exacerbate symptoms (NSAIDs, alcohol, tobacco, and certain foods). Not all patients want or need prescription medications and may prefer to explore other treatment options. Eating six small meals per day may alleviate symptoms of bloating or postprandial fullness.

Numerous medications have been used in studies of nonulcer dyspepsia. Results are confounded by different study definitions of the disorder and the lack of differentiation of symptom types. Medications include antacids, H₂-blockers, PPIs, bismuth, and sucralfate. PPIs appear to benefit ulcer like dyspepsia but not dysmotility like dyspepsia. Prokinetic agents such as metoclopramide have been poorly studied. Cisapride, which was taken off the market, showed a twofold decrease in symptoms compared to placebo. Domperidone has been shown to be superior to placebo and does not cross the blood-brain barrier to cause CNS side effects but is not available in the United States. Peppermint and caraway oils produced similar results when compared to cisapride. Motilin agonists such as erythromycin increase the rate of gastric emptying. Visceral analgesics such as fedotozine reduce gastric hypersensitivity. Buspirone and 5HT₁ agonists such as sumatriptan have shown promise. Antispasmodics such as dicyclomine have not been shown to be more effective than placebo in patients with dyspepsia. Antinausea agents such as ondansetron and perchlorperazine have been shown to modestly improve symptoms. Perchlorperazine had more side effects. Antihistamines such as dimenhydrinate and cyclizine decrease gastric dysrhythmias. Promethazine has been used to treat mild nausea. Tricyclic antidepressants have been the most extensively studied antidepressant treatment of functional dyspepsia. Selective serotonin reuptake inhibitors have shown promising results with other functional bowel diseases [eg, irritable bowel syndrome (IBS)].

Other treatment approaches include acupuncture, acupressure, and gastric electrical stimulation. No randomized, double-blind controlled trials have been performed to evaluate their effectiveness. Follow-up appointments are important to assess patient function and response to treatment.

The four main causes of abdominal pain related to the gallbladder and pancreas are biliary colic, gallstones, cholecystitis, and pancreatitis. Gallbladder-related pain usually is located in the midepigastric region with radiation to the right shoulder, right scapula, right clavicular area, or back. Pancreatitis often produces pain throughout the entire upper abdomen with frequent radiation to the back. See Chapter 33 for a detailed discussion of these and other diseases of the biliary tract and pancreas.

General Considerations

Estimates indicate that symptoms consistent with a diagnosis of IBS are present in 3–20% of adults in the Western world. Although IBS occurs worldwide, cultural and social factors affect its presentation. Women in Western countries have a higher incidence of IBS and are more likely to consult a physician. In India and Sri Lanka, men have a higher incidence. IBS symptoms are common in South Africans who live in urban zones and unusual in people who live in rural areas. In the United States, prevalence is similar in blacks and whites. Some studies show lower prevalence in Hispanics from Texas and Asians from California.

Up to 50% of individuals with symptoms consistent with IBS do not seek physician care. Many who seek care had a major life event such as a death in the family or loss of job before presenting. Primary care providers see more of these patients than GI specialists.

Pathogenesis

Physiologic changes contributing to symptoms of IBS have not been elucidated. Many theories exist, including disturbance in motility, postinfectious changes, altered perception either locally in the GI tract or in the central nervous system, visceral hypersensitivity, mucosal inflammation, autonomic nerve dysfunction, and psychological disturbance. A study using positron emission tomography (PET) scan examined the activity of the brain when GI symptoms were induced. Patients with IBS did not activate the anterior cingulate cortex associated with opiate binding but activated the prefrontal cortex associated with hypervigilance and anxiety. Studies to determine whether patients with IBS have a lower threshold of pain with colonic distention are inconclusive. Studies have not clarified whether symptoms of IBS are a normal perception of an abnormal function or an abnormal perception of a normal function.

Clinical Findings

A. Symptoms and Signs

Irritable bowel syndrome is a functional bowel disorder, without identified organic cause, in which abdominal discomfort or pain is associated with defecation or change in bowel habits and with features of disordered defecation. Diagnostic criteria developed by the Rome Consensus Committee for IBS are at least 3 days per month for the past 3 months with onset at least 6 months prior to diagnosis of abdominal discomfort or pain characterized by two of the following three features: (1) relieved with defecation, (2) onset associated with a change in frequency of stool, and (3) onset associated with change in form or appearance of the stool.

The Bristol Stool Form Scale describes seven types of stool forms. Other symptoms supporting the diagnosis of IBS include abnormal stool frequency (more than three per day or fewer than three per week), abnormal stool form (lumpy/hard or loose/watery), abnormal stool passage (straining, urgency, or feeling of incomplete evacuation), passage of mucus, and sensation of bloating or feeling of abdominal distention. Stool form has been demonstrated to reflect GI transit time. Using the Bristol Stool Form Scale and frequency of bowel movements is more precise and useful than using the imprecise terms diarrhea and constipation, since these terms have different meanings to different patients. Patients may complain of feeling constipated because of a feeling of incomplete evacuation despite having just passed soft or watery stool.

B. History

Patient history is the single most useful tool in diagnosing IBS. Continuity of care and a well-established rapport contribute significantly to obtaining accurate and complete history. A positive physician-patient interaction, psychosocial history, precipitating factors, and discussion of diagnosis and treatment with patients result in fewer return visits for IBS and lower utilization of health care resources. Chronic or recurrent abdominal pain indicates a need to assess quality of life. In a study of undergraduate students with IBS, quality-of-life scores similar to those of patients with congestive heart failure, indicated the significant impact of IBS symptoms. As noted earlier, stressful life events often precede onset of symptoms of IBS. Although stressful life events may not be the cause of IBS, they may factor into the decision by patients to seek care. The decision of women with IBS symptoms of to seek care has been shown to have a significant and positive correlation between daily stress levels and daily symptoms.

A history of abuse should be sought in patients with chronic abdominal pain. A study at a tertiary care gastroenterology clinic revealed that 60% of the overall study population reported a history of physical or sexual abuse. All were women. Self-reported history of abuse was highest for those with functional bowel disease (≤84%) and lowest for those with organic bowel disease, such as ulcerative colitis (38%).Treatment success can be affected by exploring a patient’s psychosocial stressors. Physicians should assess for abuse when considering referral to a gastroenterologist. Family physicians are uniquely positioned to assess and address issues associated with abuse.

Patients with IBS have not been demonstrated to have a higher incidence of psychiatric diagnosis such as depression, anxiety, somatization, stress, lack of social support, or abnormal illness behavior compared with other patients presenting with abdominal pain of organic origin. However, patients presenting with abdominal pain do have more psychosocial concerns than control subjects without abdominal pain. Psychosocial factors have not been shown to help in differentiating between organic and functional abdominal disease, but do help in understanding some health-seeking behaviors.

Signs or symptoms of an anatomic disease should be absent. These include fever, GI bleeding, unintentional weight loss, anemia, and abdominal mass. Laxative use should be assessed as laxatives may cause IBS-like symptoms. Patients with IBS may have had surgery, particularly appendectomy, hysterectomy, or ovarian surgery. The most common discharge diagnosis for patients hospitalized for abdominal pain is “nonspecific abdominal pain.” A study of patients discharged with this diagnosis showed that 37% of women and 19% of men met the criteria for IBS 1–2 years after discharge. Of these patients, 70% had prior attacks of abdominal pain. Only 6% of charts listed IBS in the differential diagnosis on the initial admission. Of patients presenting with acute pain of <1 week’s duration, 50% had symptoms of IBS at time of admission. Assessing for diagnostic criteria of IBS symptoms may reduce length of hospitalization, extent of testing, and cost of treatment for patients presenting with acute abdominal pain who do not need immediate surgical intervention.

C. Physical Examination

Physical examination is often unremarkable except for abdominal tenderness and an increased likelihood of abdominal scars.

D. Special Tests

No specific testing is required for diagnosis of IBS, although normal CBC and ESR may be reassuring. Patients with criteria for colon cancer screening should be examined by flexible sigmoidoscopy or colonoscopy. Other studies may include Clostridium difficile toxin if the patient has recently taken antibiotics, testing for giardiasis in endemic areas, evaluation for lactose intolerance, and serologic testing or gluten elimination diet for celiac disease.

Treatment

A. Therapeutic Relationship

A therapeutic relationship is critical to the effective management of IBS. The therapeutic relationship is achieved by a nondirective, patient-centered, nonjudgmental history, eliciting the patient’s understanding of the illness and his/her concerns, identifying and responding realistically to the patient’s expectation for improvement, setting consistent limits, and involving the patient in the treatment approach. The most effective treatment option is explanation and reassurance. A confident diagnosis based on previously outlined clinical criteria helps convey the lack of association with a higher risk of other ­diseases such as cancer and chronic nature of symptoms. Patients’ reasons for seeking care and possible contributing psychosocial issues should be assessed. Counseling regarding psychosocial stressors may not resolve all the symptoms of IBS, but may help patients cope better with symptoms.

B. Diet and Exercise

Many different dietary approaches have been tried. Patients in whom gas-forming vegetables, lactose, caffeine, or alcohol exacerbate symptoms should be counseled to minimize exposure; however, food intolerance and elimination diets have not proved effective. Dietary fiber has been shown to improve symptoms of constipation, hard stools, and straining, particularly if 30 g of soluble fiber is consumed each day. Patients often need to gradually increase the amount of fiber to improve adherence, as a sudden increase can increase symptoms of bloating and gas. The most common reason for failure of a high-fiber diet is insufficient dose. Fiber is safe and inexpensive, and should be routinely recommended, particularly to patients for whom constipation is a predominant symptom. Nondietary bulking agents have not been found more effective than placebo. Probiotics are live organisms that may benefit. Probiotics have been found to provide global improvement in IBS symptoms and abdominal pain. The exact mechanism contributing to the improvement in symptoms is not completely understood and can vary between strains and dose used. There is insufficient evidence to recommend the use of one particular strain or dose. Patients should be encouraged to consume probiotic-rich fermented foods such as yogurt, kefir, miso, tempeh, and sauerkraut. Increased physical activity has shown improvement in severity of IBS symptoms and significantly lower likelihood of worsening of symptoms. Given the multiple benefits of increased physical activity, it should be routinely recommended.

C. Complementary and Alternative Therapies

A meta-analysis of five double-blind, placebo-controlled randomized trials of peppermint oil given as a monopreparation in a dosage range of 0.2–0.4 mL suggested a significant (P <.001) positive effect compared with placebo. Randomized controlled trials of Chinese herbal medicine indicated that both a standardized herbal formulation (Tong Xie Yao Fang is a commonly used formula) as well as individualized Chinese herbal medicine treatment improved symptoms of IBS compared with placebo. Padma Lax, a Tibetan herbal digestive formula, has been used and studied in Europe and shown global improvement in symptoms. Acupuncture has been shown to be more beneficial than some antispasmodic medications. Moxibustion has been shown to be helpful compared to placebo treatments.

D. Psychological Therapies

Various psychological therapies have been studied in randomized, controlled trials comparing control therapy and a physician’s “usual management.” Psychological therapies studied include hypnotherapy, relaxation training, multicomponent psychological therapy, dynamic psychotherapy, cognitive-behavioral therapy (CBT), stress management, and self-administered CBT. Dramatic improvements in a high proportion of patients with poorly controlled IBS symptoms were seen for both individual and group hypnotherapy. Therapeutic audiotapes are an easy, low-cost alternative but may be somewhat inferior to hypnotherapy. Psychotherapy effectiveness relies on the relationship between therapist and patient, making it difficult to study in randomized, controlled trials. The quality of the data is not as strong as that for pharmacotherapy, but the number needed to treat with psychological therapies to prevent IBS symptom persistence for one patient is four. The number needed to treat with antidepressants to prevent persistent symptoms also is four. Patients with IBS are more likely to have coexisting mood disorders and anxiety. Psychological interventions should be considered.

E. Pharmacotherapy

A meta-analysis that concluded that smooth-muscle relaxants and anticholinergics were better than placebo has been criticized for methodologic inadequacies. Common GI complaints and the drugs most frequently used to treat them are as follows:

• Constipation: psyllium, methylcellulose, calcium polycarbophil, lactulose, 70% sorbitol, and polyethylene glycol (PEG) solution. A partial 5HT₄ agonist (tegaserod) was removed from the market secondary to cardiovascular side effects. Lubiprostone and linaclotide are newer agents requiring further evaluation.

• Diarrhea: loperamide, cholestyramine. Alosetron for female patients with diarrhea-predominant IBS symptoms was removed from the market secondary to risk of ischemic colitis and severe constipation but is now available again with warnings.

• Gas, bloating, or flatus: simethicone, α-galactosidase (Beano), probiotic, antibiotics. Rifaximin is expensive and not recommended for long-term treatment.

• Abdominal pain: anticholinergics and antispasmodics (dicyclomine, hyoscine, cimetropium, and pinaverium).

• Chronic pain: tricyclic antidepressants, selective serotonin reuptake inhibitors.

A positive therapeutic relationship and regular visits to a family physician can prevent a continual and costly quest by patients for a “miracle” cure.

General Considerations

Celiac disease may cause chronic abdominal pain. It is present in 0.5–1% of the US population. It is commonly associated with other autoimmune disorders, a known family history of celiac disease, and Down’s syndrome. Because of the low prevalence of disease, general screening may result in false-positive results.

Clincal Findings

Symptoms of clinical disease (or celiac sprue) include abdominal pain, diarrhea, and weight loss. It can be associated with liver enzyme abnormalities, skin problems, osteoporosis, iron deficiency anemia, flatulence, and neurologic dysfunction. Severe deficiency of vitamin D, vitamin K, or iron may be present. This may result in failure to thrive or short stature.

Mechanism of illness is an autoimmune process causing destruction of the small bowel mucosa, infiltration of mucosa with lymphatic T cells, and enlargement of crypts after repeated exposure to gluten proteins such as are found in wheat, rye, and barley.

Diagnosis

Serum immunoglobulin A (IgA) endomysial antibodies and IgA tissue transglutaminase (tTG) antibodies should be tested while patients consume a diet containing gluten. Positive results should be confirmed with endoscopic small bowel biopsy in four locations. Testing is more accurate in higher-risk populations such as those with family history, other autoimmune disorders, or iron deficiency anemia. Testing for IgA deficiency maybe helpful if clinical suspicion is high despite negative endoscopy.

Treatment

Treatment is a strict gluten-free diet. Patients should be referred to a knowledgeable nutritionist. Most patients’ symptoms will improve significantly in 3 months and have improved absorption and decreased blood loss. Risk of gastrointestinal adenoma is considerably higher in this population. Strict adherence to diet may help decrease risk.

General Considerations

Constipation can cause abdominal pain. Causes should be sought. Causes of constipation often can be addressed without laboratory studies or imaging studies.

History

History includes infrequent stooling (<3 times per week), straining in >25% of attempts, need for maneuvers to help facilitate defication such as digital evacuation, support of pelvic floor, or rare loose stools without use of laxatives. Evaluation for underlying disorders should be explored if warning signs are present. Red flags include bleeding, anemia, change in stool caliper, unintended weight loss of ≥10 lb, or abnormal findings on exam.

Physical Examination

Examination should include abdominal and rectal exam. The rectal exam should evaluate anal wink, integrity and strength of anal sphincter, presence of impacted stool, pain with palpation, presence of fissures or hemorrhoids, and presence of blood.

Diagnostic Studies

Laboratory or imaging studies are occasionally needed. Endoscopy should be performed in patients aged >50 years without prior colon cancer screening, patients with evidence of bleeding, rectal prolapse, change in stool caliper, and patients with weight loss. Simple radiologic studies can demonstrate the presence of large amounts of stool in the rectum and large bowel. Laboratory testing includes complete blood count, complete metabolic panel, and screening for hypothyroidism. A vitamin D level may be useful in some circumstances. Constipation can be evaluated further with defecography and colon transit testing. Pelvic floor dysfunction testing, including radiography, anal manometry, and electromyography, may be helpful in patients not responsive to initial treatment attempts.

Treatment

The most effective initial treatment is lifestyle modification. Modifications include increased physical activity, increased dietary fiber, and increased fluid intake. Biofeedback techniques can be used for pelvic floor dysfunction. Secondary treatment includes consistent intake of osmotic agents such as magnesium hydroxide or lactulose.

Treatment with polyethylene glycol (Miralax) may be tried. Other laxatives have shown variable effectiveness in clinical trials. These include senna, bisacodyl, methylcellulose, docusate, psyllium, and other bulking agents. Studies on probiotics and prebiotics show mixed results. Most studies were done in patients with constipation-dominant irritable bowel syndrome rather than isolated constipation. The use of some probiotics seems to improve transit time and stool consistency. Stimulants such as 5HT₄ agonists should be reserved for patients after further evaluation from a gastrointestinal specialist.

General Considerations

Appendicitis occurs in >250,000 people per year in the United States alone. Appendicitis occurs in people of any age, but is most common in later childhood through young adulthood. The presentation of appendicitis in young children and the elderly is often atypical. There is no race or gender predilection. Diagnosis in female patients can be more difficult, although males are more likely to have a perforated appendix.

Pathogenesis

The appendix is a long diverticulum extending from the cecum. Appendicitis results when the long lumen is occluded. Proliferation of lymphoid tissue, associated with viral infections, Epstein-Barr virus, upper respiratory infection, or gastroenteritis, is the most common cause of obstruction and appendicitis in young adults. Other causes of occlusion include tumors, foreign bodies, fecaliths, parasites, and complications of Crohn’s disease.

Clinical Findings

A. Symptoms and Signs

History is the most important component of diagnosis. Missed diagnosis of appendicitis can have severe sequelae. The presence of the following historical indicators should be elicited: abdominal pain, usually RLQ pain often preceded by periumbilical pain (~100% of patients); anorexia (~100%); nausea (90%), with vomiting (75%); progression of abdominal pain from periumbilical to RLQ (50%); and classic progression from vague abdominal pain to anorexia, nausea, vomiting, RLQ pain, and low-grade fever (50%).

B. Physical Examination

Careful abdominal examination with inspection, palpation, and percussion often identifies the cause of abdominal pain. Peritoneal signs, including rigidity, rebound tenderness, and guarding, and a low-grade fever [38°C (100.4°F)], are characteristic findings. Rebound tenderness and sharp pain on palpation of the McBurney point is usually elicited 2 inches from the anterior superior iliac spine on a line drawn from this process through the umbilicus. However, the size of the appendix and the location of pain with palpation may vary, so pain may occur at a remote distance from the classic McBurney point.

Pelvic examination should be performed in all women who present with RLQ pain to rule out gynecologic causes. Thorough respiratory and genitourinary examination is often helpful. Rectal examination is useful when the diagnosis remains unclear.

There is debate about the use of analgesics during the evaluation of possible appendicitis. Traditional practice suggested that the use of pain medication may mask important signs or symptoms. Studies showed mixed results, although more recent one have shown that the use of opiate medications alleviate pain without compromising, and possibly enhancing, the examination. Recent studies have shown increased pain relief on treatment when nonsteroidal anti-inflammatory pain medication is used. This contrasts with results of prior studies. Additional studies suggest that informed consent is compromised by not using adequate pain medication. Observational units and sequential examines can be helpful.

C. Laboratory Findings

Many laboratory studies are performed routinely on patients with abdominal pain. Few, if any, are truly helpful and can be misleading. Studies suggest the WBC count is seldom helpful diagnostically, although if the WBC count is <7000/mm³, appendicitis is unlikely. A WBC count of >19,000/mm³ is associated with an 80% probability of appendicitis. The presence of neutrophilia makes the diagnosis of appendicitis more likely but is not diagnostic. Increased WBCs with neutrophilia generally is accompanied by increased C-reactive protein levels. The presence of all three is not diagnostic, but the absence of all three rules out appendicitis.

Routine use of a chemistry examination is helpful to determine the level of dehydration. Urinalysis commonly shows leukocytosis and increased red blood cells and thus may be misleading. All women of childbearing age should have a pregnancy test. Urine markers of acute pediatric appendicitis may help improve diagnostic accuracy in children.

D. Imaging Studies

Imaging studies can delay treatment, increase cost, and increase radiation exposure. When the diagnosis is clear from the history and physical (H&P), rapid surgical consult should be obtained prior to imaging studies. Studies are helpful in less clear cases and may decrease rate of removal of normal appendices. Current rate of negative pathology is ~3%. CT scan is the single best test for diagnosing appendicitis. It is cost-efficient and fast, and provides low radiation exposure when specific protocols are used. Complete adominal radiographs can be misleading, are not diagnostic in most cases, and cost about the same as CT scan. CT scan can be done without contrast yet without loss of accuracy. Use of oral contrast is difficult and unnecessary in cases of suspected appendicitis. Ultrasound is less invasive than CT, is cost-efficient, and can be useful in situations when CT scan is not possible. Findings are considered “normal” only if a normal appendix is seen. An appendix located retroperitoneally or in the pelvis can be difficult to visualize. Ultrasound may be useful for gynecologic abnormalities and in evaluation of pregnant patients. It also is a good choice for children because of lack of contrast and patient compliance. Focused spiral CT without contrast can be performed in less than an hour and is very sensitive and specific for appendicitis. Use of contrast may be helpful in certain cases, especially in patients who are thin or older, and those with unclear etiology.

Treatment

Treatment consists of surgical removal of inflamed appendix via laparotomy or laparoscopy. Laparotomy is faster, simpler, and less expensive, and has a lower rate of complications. Laparoscopy allows visualization of other possible causes of pain. Recent advances in surgical technology have shown other benefits of laparoscopic procedures: faster recovery, shorter hospital stay, and decreased postoperative pain. Choice of surgical options should be done on an individual basis and based on surgical experience and opinion at time of surgery. A few small studies suggest that treatment with antibiotics and observation can result in temporary resolution of symptoms but generally result in high reoccurrence rates. This may be an option for medically unstable patients or where surgery is not readily available.

General Considerations

Inflammatory bowel disease (IBD) is a broad category encompassing several disease subtypes. The most common are ulcerative colitis (UC) and Crohn’s disease (CD). Other inflammatory bowel conditions, including acute infectious colitis and gastroenteritis, are addressed elsewhere. The Human Genome Project has shown a clear genetic predisposition to both UC and CD. Prevalence of CD is much higher in Caucasians, especially in those of Jewish descent. Onset of IBD is most commonly seen at ages 15–30 years. Specific gene loci have been identified showing a correlation with susceptibility to either CD or UC. This susceptibility seems to be affected by environmental factors such as smoking and microflora of the gut. There appears to be an inappropriate inflammatory response to normal intestinal microbiology.

Environmental factors may make IBD more prevalent in people who work indoors and less prevalent in manual laborers who work outdoors. There is a 20–50% increase in the prevalence of IBD in first-degree relatives and a 50–100-fold increase in the offspring of patients with IBD. Risk factors, including work environment and diet, differ among subtypes of IBD. Smoking appears to decrease the risk of UC but increases risk and severity of CD. Birth control pills seem to increase the risk of CD. Both diseases are more prevalent in urban areas, suggesting environmental factors such as pollution, chemical exposure, and sun exposure. Patients with IBD have a higher incidence of ankylosing spondylosis, cholangitis, and psoriasis.

Pathogenesis

Increased knowledge of genetic susceptibility has increased the understanding of pathogenesis. Environmental factors seem to allow for altered immunologic responses to normal intestinal flora and destruction within the mucosa of the GI tract. CD appears to be related to altered macrophage function. UC is more likely related to a pathologic inflammatory response to normal intestinal microflora. Decreased bifidobacteria and lactobacilli levels are noted in patients with active CD compared with those in remission and healthy controls. Fusobacterium varium may be a factor in pathogenesis of UC. Changes within the microflora, combined with the immune response, result in altered mucosal barriers, luminal antigens, and macrophage function.

Clinical Findings

A. Symptoms and Signs

Inflammatory bowel diseases usually present with abdominal pain, bleeding, vomiting, diarrhea, abdominal cramping, muscle spasm, weight loss, and anemia. Abdominal pain is more common in patients with CD. Patients with UC almost always present with perirectal pain and bloody diarrhea. CD can be more difficult to differentiate from other diseases based on history and physical examination alone. CD can present anywhere from mouth to anus (skip lesions). UC is focused at the rectum and colon. RLQ pain is present in most patients with CD, reflecting involvement of the terminal ileum in 85% of cases. Only the mucosa is affected in UC. CD can affect the entire bowel wall, resulting in more destructive lesions causing fistula, bowel obstruction, and extraintestinal lesions. CD can be associated with liver, skin, joint, and ocular lesions.

B. Physical Examination

Physical examination findings are not specific. Evaluation of the rectum for evidence of fissures, ulceration, or abscess can be helpful. Fullness or a palpable mass suggests abscess. Examination often reveals nonspecific generalized tenderness, with focal findings dependent on extent and activity of disease. Skin examination may be useful. CD is associated with erythema nodosa and aphthous stomatitis. UC is associated with pyoderma gangrenosa. Growth retardation and delayed sexual maturation can occur from disease process and medications used to treat disease.

C. Laboratory Findings

Recommended laboratory tests include ESR; C-reactive protein; CBC; liver function tests (LFTs); albumin and prealbumin; electrolytes; stool studies; and vitamin B₁₂, folate, and vitamin D levels. ESR is elevated in 80% of patients with CD and 40% of patients with UC. Elevated C-reactive protein is present in 95% of symptomatic patients with CD. Anemia from iron deficiency and blood loss is common. Leukocytosis with increased eosinophilia is noted often. Liver involvement in patients with CD (eg, sclerosing cholangitis, autoimmune hepatitis, and cirrhosis) may affect LFTs. Albumin and prealbumin are indicators of malnutrition from malabsorption. Stool studies rule out infectious etiologies of colitis. Perinuclear antineutrophil antibody (pANCA) titer is useful to differentiate between CD and UC. pANCA is present in ~6% of patients with CD and 70% of patients with UC. Saccharomyces cervisiae (ASCA) is found in ~50% of individuals with CD and correlates closely with involvement of small bowel, stenosing lesions, and perforation.

D. Imaging Studies

Colonoscopy is the most accurate diagnostic test, allows direct visualization of mucosa, and biopsy. It is not recommended in acute active disease because of the risk of perforation. Histological variances help differentiate CD from UC. Visualizaion of skip lesions, cobblestoning, and strictures suggest CD. Colonoscopy with ileoscopy, capsule endoscopy, CT scan, and small bowel follow-through help evaluate all areas of disease. Capsule endoscopy, when combined with other testing, improves sensitivity to >90% and improves specificity. Capsule endoscopy is contraindicated in patients with known or suspected stricture. MRI and ultrasound help identify extraintestinal areas and complications of disease. Plain films are most helpful identifying toxic megacolon, and the “thumbprinting” sign (seen with bowel wall edema) and may identify strictures, skip lesions, and perforation. The classic string sign is seen on barium enema. Abdominal CT is helpful in identifying abscess, fistula, bowel wall ­thickening, and fat striation.

Treatment

Management of IBD includes medical therapy, nutritional support, psychological support, and surveillance for cancer. Familial and genetic counseling is important to help family members cope with exacerbations of the disease and because of the strong pattern of inheritance.

Mesalamine products are used for mild to moderate disease and believed to have anti-inflammatory and immunosuppressive properties and include mesalamine, balsalazide, olsalazine, and sulfasalazine. All can cause nausea, headache, and abdominal pain. Antibiotics, including metronidazole and ciprofloxacin, are widely used, and have anti-inflammatory as well as anti-infectious properties. Mild cases can improve with use of budesonide. Moderate to severe cases may be treated with prednisone. Severe cases are treated with azathioprine and 6-mercaptopurine. Immune modulating medications are used for long-term maintenance of remission in combination with steroids or anti-TNF preparations such as infliximab, adalimamab, and certolizumab pegol. Methotrexate use can enable the practitioner to wean the patient from steroids but may cause bone marrow suppression, leukopenia, hepatic fibrosis, and pneumonitis.

Patients with severe disease require hospital admission for bowel rest, parenteral nutritional support, and corticosteroids. Increased use of immunomodulators has allowed for less use of systemic steroids.

Nutritional therapy is helpful to maintain remission and decrease likelihood of nutritional deficiency due to malabsorption, especially in children. Research suggests that the use of fecal basteriotherapy, helminthic therapy, and other biologics may have a role in treatment by altering the bacterial flora of the gut.

Surgical therapy is often required. Approximately 85% of patients with persistent elevation of C-reactive protein and frequent liquid stools require total colectomy. Strictures and abscess formation may necessitate surgical excision of small segments of bowel or strictureplasty. Surgery is used for intractable bleeding, abscess, or fistula formation. Patients with limited resection have fewer stools, and better anorectal function.

Risk of adenocarcinoma is increased in patients with chronic colon disease. Risk of cancer development in UC is equivalent to CD with colon involvement. Biannual colonoscopy and biopsy is recommended for disease present for ≥10 years. Risk of other cancers, such as adenocarcinoma of the jejunum and ileum (when involved), lymphoma, and squamous cell carcinoma of the vulva and rectum, is increased in CD.

General Considerations

Diverticulitis occurs in 10–25% of patients with diverticulosis. In the twentieth century, the incidence of diverticulosis increased as fiber intake decreased. In addition to insufficient fiber, age is the single greatest risk factor. Typically, diverticulosis is seen in patients aged ≥60 years, is uncommon before age 40, and is present in 50% of people aged >90 years. Patients of western European descent have increased prevalence of left-sided diverticula. Patients of Asian descent have increased prevalence of right-sided diverticula.

Pathogenesis

The pathology of diverticulitis is directly related to the anatomy of the bowel wall. True diverticula consists of outpouching of all three layers of the wall: mucosa, submucosa, and muscular layer. Most cases of diverticulitis involve pseudodiverticula with herniation of the mucosa and submucosa through the muscular layer. Diverticula tend to form in rows between mesenteric and lateral teniae. The area of penetration of the vasa recta has the greatest muscular weakness and is therefore the most common site of herniation.

Lack of dietary fiber contributes to the development of diverticula. As fiber content of the stool decreases, colonic pressure increases and transit time decreases. As we age, increased cross-fibers within the collagen and elastin render the bowel wall less compliant, resulting in high pressure in the colon, and essentially blowing out areas of weakness in the colon wall. Previous recommendation to avoid seeds, nuts, and corn were based on the misconception that these foods caused aggravation of divericulitis. Recent studies do not support avoiding these foods and suggest that higher intakes of corn and nuts could help decrease the incidence of diverticulitis, at least in men.

Diverticulitis occurs when infection is associated with one or more of these diverticula. Micro- or macroperforations of diverticula may occur, resulting in bowel contents contacting the peritoneum and infecting the pericolonic fat, mesentery, and associated organs. This can localize and result in the development of an abscess, peritonitis, or fistula. A fistula can form between the colon and an abdominal organ. A colovesical fistula, connecting the colon and urinary bladder, is most common.

Clinical Findings

A. Symptoms and Signs

Left lower quadrant (LLQ) pain occurs in 93–100% of patients. Pain may be right-sided, especially in patients of Asian descent. A duration of ≥3 days of RLQ pain is suggestive of diverticulitis rather than appendicitis. Patients commonly have nausea, vomiting, constipation, or diarrhea. Dysuria and urinary frequency may be present. Complicated diverticulitis, as with a colovesical fistula, can present with recurrent urinary tract infections. In macroperforation, diffuse abdominal pain is present.

B. Physical Examination

Abnormal vital signs, including tachycardia and temperature of ≥38.1°C (≥100.7°F), give supporting evidence for the diagnosis of diverticulitis. Fever is present in most patients. Examination should include complete abdominal examination. Signs suggestive of diverticulitis include tender LLQ or less frequently RLQ tenderness, signs of peritoneal irritation such as guarding or tenderness to percussion, and occasional presence of a tender mass, suggesting the presence of an abscess. Rectal examination may demonstrate rectal tenderness or mass.

C. Laboratory Findings

Patients suspected of having diverticulitis should undergo a CBC and urinalysis. The WBC count is increased in more than two-thirds of patients, with a high prevalence of polymorphonuclear leukocytes, Anemia may be noted if there is associated diverticular bleeding. Urinalysis can show evidence of inflammation if there is irritation of the peritoneum surrounding the bladder or evidence of infection if a fistula is present.

D. Imaging Studies

Flat and upright abdominal films, or CT of the abdomen and pelvis if the diagnosis is unclear, should be obtained. Abdominal films can show evidence of free air, ileus, or mass. CT scan shows a thickened colonic wall and allows insertion of percutaneous drainage if an abscess is present, allowing for delay in surgical intervention. Similar findings can be seen on ultrasound, but CT best confirms diverticulitis by revealing the presence and location of an abscess and allowing for identification of other pathologic processes such as cancer, Crohn’s disease, and appendicitis. Ureteral obstruction, fistula, or air in the bladder can be seen. Colonoscopy should be done 4–6 weeks after resolution of diverticulitis to evaluate for concomitant cancerous lesions, and if IBD is suspected.

Treatment

Treatment depends on severity of disease and the health of the patient. Outpatient treatment includes clear liquid diet and oral broad-spectrum antibiotics, although research does not show clear benefit with the use of antibiotics. Current recommendations include ciprofloxacin and metronidazole for 7–10 days, but CDC or Sanford antibiotic guidelines should be followed because of changing antibiotic resistance. Medications such as morphine increase colonic pressure and should be avoided. Meperidine is the best choice for pain control because it decreases colonic pressure. Steroids and NSAIDs should be avoided because of the increased risk of GI bleeding and perforation.

Patients with signs and symptoms of inflammation, such as fever and leukocytosis, require hospitalization. Treatment includes complete bowel rest, intravenous fluids, and intravenous broad-spectrum antibiotics. A nasogastric tube is not needed unless there is significant ileus or obstruction. Most patients improve in 48–72 hours, at which time they can resume their regular diet, receive oral antibiotics, and be discharged home with close follow-up. A high-fiber diet is recommended for all patients after recovery. Surgical resection is recommended for perforation or uncontrolled bleeding.

Surgery is seldom recommended after a first attack, given a recurrence rate of 20–30%. However, this rate increases with each subsequent attack, as does the risk of associated morbidity. Therefore, surgery should be considered after the second or third attack. Surgical intervention can be considered with a first attack for immunocompromised patients because of their increased risk of morbidity and mortality. Surgical intervention is done on a case-by-case basis for complicated diverticulitis. Allowing decreased inflammation of the bowel wall prior to resection and anastomosis by use of percutaneous drainage and antibiotic treatment improves outcome. Morbidity and mortality rates are improved when primary anastomosis can be performed, rather than a two-stage approach with colostomy. Patients aged <40 years at the first attack have an increased lifelong risk, due to the increased life expectancy, although risk with each attack is not increased. These cases are determined on an individual bases based on frequency and severity of attacks.

Meckel’s Diverticulum

Meckel’s diverticulum is a congenital anomaly of the GI tract in which an outpouching portion of intestine, derived from the fetal yolk stalk, contains gastric or pancreatic tissue. Patients can present with abdominal pain, nausea, vomiting, or intestinal bleeding. Complications include diverticulitis, intussusception, perforation, and obstruction. The best diagnosistic test is the technetium-99m pertechnetate scan. Treatment is surgical.

There are many presentations of abdominal wall pain because of the multiple different causes of abdominal wall pain. Causes include hernias, herpes zoster, neuromas, hematomas of the abdominal wall or rectus sheath, ­desmoid tumor, endometriosis, myofascial tears, intraabdominal adhesions, neuropathies, slipping rib syndrome, and general myofascial pain. Examination findings suggesting abdominal wall pain include lack of evidence for an intraabdominal process; pain unrelated to meals or bowel function; pain related to posture, a trigger point; and a positive Carnett sign. This is elicited by having the patient tense the abdominal muscles. Areas of tenderness after tensing are considered positive and suggest abdominal wall rather than visceral pain.

Hernias

Types of hernias include inguinal, femoral, umbilical, epigastric, spigelian, and Richter hernias. Hernias are more commonly identified by exam rather than history. History can be confusing with herniation of bowel wall or omentum. Bowel herniation causes visceral pain and obstruction. Omentum herniation causes visceral pain without signs of obstruction. A history of prior surgery, especially laparoscopic surgery, increases the likelihood of a hernia.

Men more typically develop inguinal hernias. Women tend to develop femoral hernias. Umbilical and epigastric hernias are more common in obese or gravid patients. Spigelian hernias, a hernia along the border of the arcuate ligament, is most common in athletes.

Richter hernia is defined by the pathology rather than the location of the hernia. The side of the bowel wall herniates, rather than the entire bowel segment. Often the hernia produces a slight bulge that may be confused with adenopathy or fat. Because this type of hernia results in subtle findings, there often is a delay in diagnosis and a higher fatality rate. Richter hernia is generally found in women aged >50 years, but the incidence is increasing in young men, due to the increased frequency of laparoscopic procedures. Because the instruments used for laparoscopy are so small, the abdominal wall defect remaining after surgery may allow only a portion of the bowel wall to herniate. The resultant tight hernia causes strangulation of the tissue passing through. Prior surgical sites must be examined. Erythema at these sites can be a sign of local infection, fistula formation, or an inflammatory process at the site of scarring.

Although a CT scan can identify hernias, they are often overlooked unless the radiologist is focused on thorough examination of the abdominal wall.

Hernias are best treated surgically. If surgery is contraindicated, hernias causing pain or posing risk of bowel obstruction can be treated with a truss or other restrictive garment.

Rectus Sheath Hematoma

Rectus sheath hematomas can be difficult to diagnose. They tend to occur more commonly in elderly or pregnant patients. The epigastric vessels are sheared, resulting in intramuscular bleeding. Shearing can occur from trauma or twisting motions. History is the most important factor in directing the clinician. A history of unilateral midabdominal pain, use of anticoagulants such as aspirin or warfarin, and abdominal trauma are all important risk factors. Pain is unilateral and worse when patients tense their abdominal muscles. There is often a palpable mass within the rectus sheath.

Coagulation studies and blood count are the most useful laboratory studies. Helpful imaging studies include CT, ultrasound, and MRI. Ultrasound is the cheapest and most useful study if the diagnosis is highly suspected. CT is more useful for identifying other possible causes. MRI sometimes helps if the diagnosis remains unclear. Treatment is generally expectant, but severe cases may warrant reversal of coagulation abnormalities, administration of fluids, or surgical evacuation and ligation or coagulation of vessels.

Herpes Zoster

Herpes zoster should be suspected when there is an abrupt onset of severe abdominal wall pain. Pain associated with zoster can precede the rash by >1 week, although more commonly by 2–4 days. Zoster occurs most frequently in patients aged >50 years. Postherpetic neuralgia (PHN) causes persistant pain, especially in patients aged >60 years. Thorough history and close follow-up are the best measures to establish the diagnosis. Varicella vaccine may help prevent zoster. Treatment of acute zoster with acyclovir, valacyclovir, or famciclovir in combination with a prednisone taper seems to decrease incidence and severity of PHN. Treatment of PHN has proved difficult. Many modalities have been tried with minor success, incuding analgesics, narcotics, nerve stimulation, antidepressants, capsaicin, biofeedback, and nerve blocks.

Other Causes of Abdominal Wall Pain

Surgical scars are the location of many causes of abdominal wall pain. Hernias and endometriosis can occur at these site. Neuromas often form at the border of scars. Other unusual causes include desmoid tumors, myofascial tears, and intraabdominal adhesions. Desmoid tumors are dysplastic tumors of the connective tissue, tend to form in young adults, and can be identified only after surgical removal. Myofascial tears and intraabdominal adhesions occur most frequently in athletes.

Treatment

Trigger points often reproduce abdominal wall pain. Finding this point can help both diagnosis and treatment. Trigger points are often found along the lateral border of the rectus abdominis muscle, where nerve roots become stretched, compressed, and irritated. Points are also found at areas of tight-fitting clothing or at insertion points of muscles. The Carnett sign, described earlier, is useful for diagnosis of trigger points. Relief of many causes of abdominal wall pain can be achieved by injection of lidocaine or its equivalent into the point of most tenderness. This treatment can be diagnostic and therapeutic. Insertion of the needle into the correct point elicits intense pain, which improves dramatically after injection. Areas requiring more than one injection can be injected with a small amount of steroids. Steroids should be avoided in areas near hernias or into fascia, as they can cause hernia formation. Dry needling has proved useful, but initial treatment may cause more pain. Patients with severe needle aversion may benefit from a therapeutic trial of a transcutaneous lidocaine patch. Pain clinics may help in more difficult cases.

Management of this type of pain can be difficult. Patient education and reassurance are important. Preventing further unnecessary testing can be avoided by decreasing patients’ concerns about the pain. Tricyclic antidepressants can be useful at low doses.

Gynecologic causes of abdominal pain can be separated into three categories: acute causes in nonpregnant patients, chronic problems in nonpregnant patients, and acute causes in pregnant patients. Acute causes include PID, adnexal torsion, ruptured ovarian cyst, hemorrhagic corpus luteum cyst, endometriosis, and tuboovarian abscess. Chronic causes in nonpregnant patients include dysmenorrhea, mittelschmerz, endometriosis, obstructive müllerian duct abnormalities, leiomyomas, cancer, and pelvic congestion syndrome. Causes in pregnant patients include ectopic pregnancy, retained products of conception, septic abortion, and ovarian torsion. Psychological factors greatly contribute to abdominal and pelvic pain. Patients can present with acute pain after a sexual assault.

A wide differential, careful history, and pregnancy test should be considered when evaluating women and girls with abdominal pain. History includes last menstrual period, detailed menstrual history, sexual history including possible assault, and family history. Physical examination includes careful abdominal, pelvic, and rectovaginal examinations. Laboratory evaluation is based on findings from the physical examination. LFTs can help identify Fitz-Hughes and Curtis syndromes, especially in the presence of RUQ pain.

Pelvic inflammatory disease occurs in 11% of US women of reproductive age, although it is rare in pregnancy. Numerous biological factors contribute to a higher incidence of PID in adolescents, including lower prevalence of protective chlamydial antibodies, more penetrable cervical mucus, and larger zones of cervical ectopy with more vulnerable columnar cells. Other risk factors increasing the likelihood of PID include early age at first sexual intercourse, higher number of lifetime partners, or a new partner within the last 30–60 days. Diagnosis of PID requires the presence of abdominal pain, adnexal pain, cervical motion tenderness, and at least one of the following: temperature of >38.3°C (>101°F), vaginal discharge, leukocytosis with a cell count of >10,500/mm³, positive cervical cultures, intracellular diplococci, or WBCs on vaginal smear. Treatment depends on whether the patient requires inpatient or outpatient treatment. Inpatient treatment is required for surgical emergencies, pregnancy, no response to outpatient therapy in 72 hours, nausea and vomiting, or immunodeficiency.

Endometriosis is found in 15–32% of women undergoing laparoscopic evaluation of abdominopelvic pain. The pain is generally cyclical but can present acutely with ruptured ovarian endometrioma. A retroverted, fixed uterus with ash spots on the cervix suggests endometriosis. Conservative treatment includes NSAIDs and oral contraceptive use.

Most gynecologic causes of abdominal pain can be evaluated by ultrasound. Laparoscopy may be needed and can be therapeutic as in ovarian torsion. CT may help delineate unclear ultrasound findings. Consultation with a gynecologist often is warranted.