Diverticulitis

Diverticulitis is inflammation or infection of colonic diverticula, most often in the sigmoid colon. Diverticula are small pouches protruding through weak spots in the colon wall. The condition arises in people with diverticulosis and is thought to result from microperforation and local infection of one or more diverticula, often in the setting of increased intraluminal pressure and aging.

Symptoms typically include acute left lower quadrant abdominal pain, fever, nausea, and changes in bowel habits. Exam may reveal tenderness; in the elderly or immunocompromised the presentation can be atypical.

Diagnosis is clinical in typical cases. CT with contrast is the preferred imaging test and helps distinguish uncomplicated from complicated disease. Leukocytosis is common. Ultrasound can be used where CT is not available. After an acute episode, colonoscopy or CT colonography is usually delayed for about six weeks to exclude cancer.

Uncomplicated diverticulitis involves infection limited to diverticula; complicated disease includes abscess, perforation, peritonitis, fistula, or obstruction. Complications may require hospitalization and more intensive therapy.

Treatment ranges from outpatient management for uncomplicated disease to hospitalization for severe or complicated cases. Outpatients may receive analgesia, rest, and a short course of oral antibiotics; some guidelines permit observation without antibiotics in mild cases. Diet typically shifts to high fiber after symptoms improve.

Prevention focuses on a high-fiber diet, regular activity, weight control, and avoidance of nonsteroidal anti-inflammatory drugs. Many patients have recurrent episodes, but prognosis is generally favorable with timely treatment; serious complications are uncommon but can occur.