DIVERTICULITISDiverticulitis occurs as a result of impaction of diverticula with fecaliths, which create an inflammatory process, sometimes leading to erosion and perforation of the colonic wall. Simple diverticulitis, which occurs in the majority of patients, is not associated with complications; these patients usually respond to medical therapy. Complicated diverticulitis involves perforation, obstruction, abscess, or fistula. This occurs in a quarter of patients with the first episode and requires surgery.Most patients with acute sigmoid diverticulitis have left lower quadrant pain, fever, and leukocytosis. A mass may be palpated on pelvic and rectal examination. CT scanning is the diagnostic technique of choice and typically reveals thickening of the bowel wall, streaky mesenteric fat and associated abscess.Patients with mild symptoms in the absence of systemic signs and symptoms may be treated on an outpatient basis with a low-residue diet and broad-spectrum oral antibiotics for 7 to 10 days. Hospitalization is required for significant fever, more severe signs and symptoms, or inability to tolerate an oral diet. Treatment consists of bowel rest, intravenous antibiotics, and intravenous fluids. Persistent fever and leukocytosis after 48 hours suggest an unresolving abscess. Up to one third of patients will go on to have a second episode of diverticulitis, and elective surgery should be considered in these patients.Surgery is mandatory for patients with complications of diverticulitis. Percutaneous drainage of an abscess may be used preoperatively to simplify a subsequent surgery, or in some cases eliminate the need for surgery. The antibiotic regimens recommended for secondary peritonitis are also appropriate for antimicrobial management of diverticular complications.*100/348/5*