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.
ESSENTIALS OF DIAGNOSIS
Acuity, onset, and duration of symptoms.
Quality, location, and radiation of pain.
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.”
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).
Table 31–1.Common causes of abdominal pain by location. ||Download (.pdf) Table 31–1.Common causes of abdominal pain by location.
Ruptured ovarian cyst
Sickle cell crisis
Abdominal wall pain—multiple causes
Ruptured aortic aneurysm
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.
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.
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.
ESSENTIALS OF DIAGNOSIS
Inspect, auscultate, palpate, and percuss abdomen.
Palpate for tenderness and rebound tenderness.
Assess bowel sounds
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.
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.
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.
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.
A pelvic examination may be indicated in female patients with abdominal pain.
ESSENTIALS OF DIAGNOSIS
CBC, electrolytes, BUN, creatinine, and glucose are useful in most patients.
All women of childbearing age should have a pregnancy test.
Consider iron studies for adults aged >50 years.
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.
ESSENTIALS OF DIAGNOSIS
A CT scan is the test of choice for acute abdominal pain.
An ultrasound (US) is the test of choice for RUQ pain.
Colonoscopy should be considered for abdominal pain in all patients aged >50 years.
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.