Diverticulitis

Diverticulitis is an inflammation of the diverticulum that can lead to phlegmon of the intestinal wall, peritonitis, perforation, fistula, or abscess formation. The initial symptom is abdominal pain. Diagnosis is made by CT of the abdomen. Treatment of diverticulitis includes antibiotic therapy (ciprofloxacin or third-generation cephalosporins with metronidazole) and sometimes surgery.

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What causes diverticulitis?

Diverticulitis occurs when there is micro- or macroperforation of the diverticulum mucosa with release of intestinal bacteria. The inflammation that develops remains localized in approximately 75% of patients. The remaining 25% may develop an abscess, perforation into the free abdominal cavity, intestinal obstruction, or fistulas. The bladder is often involved in fistulas, but the small intestine, uterus, vagina, abdominal wall, or even the thigh may also be involved.

Diverticulitis is severe in older patients, especially those taking prednisone or other drugs that increase the risk of infection. Almost all of the most severe cases of diverticulitis are localized in the sigmoid colon.

Symptoms of diverticulitis

Diverticulitis is usually accompanied by pain, tenderness in the left lower quadrant of the abdomen, and fever. Peritoneal signs of diverticulitis may occur, especially with abscess or perforation. Fistula formation may manifest as pneumouria, vaginal stool, and development of phlegmon of the abdominal wall, perineum, or thigh. Patients with intestinal obstruction develop nausea, vomiting, and abdominal distension. Bleeding is uncommon.

Diagnosis of diverticulitis

Diverticulitis is clinically suspected in patients with a known diagnosis of diverticulosis. However, because other diseases (eg, appendicitis, colon or ovarian cancer) may have similar features, testing is required. CT with oral or intravenous contrast is most useful; however, results obtained in approximately 10% of patients do not differentiate diverticulitis from colon cancer. Laparotomy may be necessary for definitive diagnosis.

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Treatment of diverticulitis

In uncomplicated cases, the patient can be treated on an outpatient basis with rest, liquid diet, and oral antibiotics (eg, ciprofloxacin 500 mg twice daily or amoxicillin/clavulanate 500 mg three times daily with metronidazole 500 mg four times daily). Symptoms of diverticulitis usually resolve quickly. The patient is gradually introduced to a soft, low-fiber diet and daily psyllium seed preparations. After 2 to 4 weeks, the colon should be examined by barium enema. After 1 month, a high-fiber diet can be resumed.

Patients with more severe symptoms (pain, fever, leukocytosis) should be hospitalized, especially those taking prednisolone (higher risk of perforation and generalized peritonitis). Treatment includes bed rest, fasting, intravenous fluids, and antibiotics (eg, ceftazidime 1 g intravenously every 8 hours along with metronidazole 500 mg intravenously every 6-8 hours).

In approximately 80% of patients, treatment is effective without surgery. If an abscess forms, percutaneous drainage (under CT control) is possible. If the procedure is effective, the patient remains in the hospital until symptoms disappear, and a gentle diet is prescribed. Irrigoscopy is performed more than 2 weeks after all symptoms have resolved.

Surgical treatment of diverticulitis

Emergency surgical treatment of diverticulitis is indicated in patients with perforation into the abdominal cavity or generalized peritonitis, as well as in patients with severe symptoms not responding to noninvasive treatments within 48 hours. Increasing pain, tenderness, and fever are signs that indicate the need for surgical treatment. Surgery should also be considered in patients with any of the following: a history of two or more mild exacerbations of diverticulitis (or one exacerbation in a patient younger than 50 years); a persistently palpable tender mass; clinical, endoscopic, or radiographic features suggestive of cancer; dysuria associated with diverticulitis in men (or in women who have had a hysterectomy), as this sign may be a precursor to perforation into the bladder.

The involved portion of the colon is resected. In patients without perforation, abscess formation, or significant inflammation, the ends may be anastomosed primarily. In other cases, patients undergo a temporary colostomy with subsequent restoration of passage after the inflammation has resolved and the general condition has improved.