Diverticulitis

For further information, see CMDT Part 15-36: Diverticular Disease of the Colon

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

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

• Perform radiologic imaging (CT colonography or barium enema) only after resolution of clinical symptoms to document extent of diverticulosis or presence of fistula

• CT scan of the abdomen indicated

  • To confirm diagnosis

  • In patients who do not improve rapidly after 2–4 days of empiric therapy

  • In severe disease to diagnose abscess

  • Presence of colonic diverticula and wall thickening, pericolic fat infiltration, abscess formation, or extraluminal air or contrast suggests diagnosis

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 can be managed with conservative measures

• Mild diverticulitis (mild symptoms and no peritoneal signs)

  • Clear liquid diet

  • 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

• Surgery in two stages for abscesses for which catheter drainage is not possible or helpful

  • Diseased colon is resected, temporary colostomy of proximal colon is created, and distal colonic stump is either closed (forming a Hartmann pouch) or exteriorized as a mucous fistula

  • Weeks later, colon is reconnected electively

Therapeutic Procedures

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

Complications

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

• Stricturing of the colon with partial or complete obstruction

Prognosis

• Diverticulitis recurs in 15–30% 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

Prevention

• High-fiber diet

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