Diverticulitis

Essentials of Diagnosis

• Acute abdominal pain and fever

• Left lower abdominal tenderness and mass

• Leukocytosis

General Considerations

• Defined as macroscopic inflammation of a diverticulum that may reflect a spectrum from inflammation alone, to microperforation with localized paracolic inflammation, to macroperforation with either abscess or generalized peritonitis

• Diverticulosis

  • Present in 25% of adults over age 40

  • Increases with age

  • Most cases are asymptomatic

• Diverticulitis occurs in 10–20% of patients with diverticulosis

Symptoms and Signs

• Abdominal pain, mild to moderate, aching, usually in the left lower quadrant

• Constipation or loose stools

• Nausea and vomiting

• Low-grade fever

• Left lower quadrant tenderness

• Palpable left lower quadrant mass

• Generalized abdominal pain and peritoneal signs in patients with free perforation

Differential Diagnosis

• Perforated colorectal cancer

• Infectious colitis, eg, Campylobacter, Clostridioides difficile

• Inflammatory bowel disease

• Ischemic colitis

• Appendicitis

• Gynecologic

  • Pelvic inflammatory disease

  • Tubo-ovarian abscess

  • Ovarian cyst or torsion

  • Ectopic pregnancy

  • Mittelschmerz

  • Endometriosis

• Urinary calculus

• Gastroenteritis

Laboratory Tests

• Leukocytosis, mild to moderate

• Stool occult blood test positive, but hematochezia is rare

Imaging Studies

• Indications for CT scan of the abdomen

  • Suspected diverticulitis, especially in patients with fever, leukocytosis, and signs of sepsis or peritonitis

  • Evidence of complicated disease in immunocompromised patients

  • Presentation of mild symptoms for first time to look for evidence of diverticulitis (colonic diverticula, wall thickening, pericolic fat infiltration) and to exclude other causes of abdominal pain

• Patients who respond to acute medical management should undergo complete colonic evaluation with colonoscopy or radiologic imaging CT colonography) 4–8 weeks after resolution of clinical symptoms to exclude colorectal cancer (which may mimic diverticulitis)

• Endoscopy and colonography are contraindicated during the initial stages of an acute attack because of the risk of free perforation

Diagnostic Procedures

• Colonoscopy

  • Recommended in patients over age 50 who have not undergone appropriate screening

  • Should be considered in other high-risk patients, especially those with suspicious radiologic imaging, diverticulitis with complications or protracted symptoms, or family history of colorectal cancer

  • Contraindicated during acute attack

  • Perform only after resolution of clinical symptoms to document extent of diverticulitis and to exclude other clinical disorders

Medications

• Most patients with uncomplicated disease can be managed with conservative measures

• Mild diverticulitis (mild symptoms and no peritoneal signs)

  • Clear liquid diet for 2–3 days

  • Broad-spectrum oral antibiotics with anaerobic activity, such as amoxicillin and clavulanate potassium, 875 mg/125 mg twice daily orally; or metronidazole, 500 mg three times daily orally; plus either ciprofloxacin, 500 mg twice daily orally, or trimethoprim-sulfamethoxazole, 160/800 mg twice daily orally, for 7–10 days

• Severe diverticulitis (high fevers, leukocytosis, or peritoneal signs)

  • Nothing by mouth

  • Intravenous fluids

  • Nasogastric tube suction if ileus is present

  • Intravenous antibiotics targeting both anaerobic and aerobic (gram-negative) bacteria, such as either single-agent therapy with a second-generation cephalosporin (eg, cefoxitin), or piperacillin-tazobactam, or ticarcillin clavulanate; or combination therapy (eg, metronidazole or clindamycin plus an aminoglycoside or third-generation cephalosporin [eg, ceftazidime, cefotaxime]) for 7–10 days

Surgery

• Indications for surgery

  • Generalized peritonitis

  • Large undrainable abscesses

  • Clinical deterioration despite medical management and percutaneous drainage

• Following recovery from complicated diverticulitis, a subsequent elective one-stage surgical resection is generally recommended to reduce recurrent episodes of complicated disease

Therapeutic Procedures

• Percutaneous catheter drainage of localized abdominal abscess, with subsequent single-stage elective surgical resection of diseased segment of colon

Complications

• Phlegmon

• Abscess

• Perforation

• Peritonitis

• Sepsis

• Chronic inflammation or an untreated abscess may lead to

  • Smoldering disease (ongoing pain, leukocytosis)

  • Fistula formation that may involve the bladder, ureter, vagina, uterus, bowel, and abdominal wall

  • Stricturing of the colon with partial or complete obstruction

Prognosis

• Diverticulitis recurs in 15–20% of patients treated with medical management over 10–20 years; however, < 5% have more than two recurrences

• Recurrent mild attacks may warrant elective surgical resection in selected patients

When to Refer

• Failure to improve within 72 hours of medical management

• Presence of significant peridiverticular abscesses (4 cm or larger) requiring possible percutaneous or surgical drainage

• Generalized peritonitis or sepsis

• Recurrent attacks

• Chronic complications including colonic strictures or fistulas

When to Admit

• Severe pain or inability to tolerate oral intake

• Signs of sepsis or peritonitis

• CT scan showing signs of complicated disease (abscess, perforation, obstruction)

• Failure to improve with outpatient management

• Immunocompromised or frail, elderly patient