Therapeutic options in acute diverticulitis. Diverticulitis is a serious intra-abdominal infection that ultimately afflicts about one in four patients having colonic diverticulosis. The illness may be indolent or fulminant, depending on the degree of colonic spillage and its containment. Most patients require hospitalization, and medical therapy suffices in about three fourths. Those who fail aggressive medical management and those with recurrent acute attacks, diffuse peritonitis, abscess, persistent obstruction, or fistulization require surgical intervention. Abdominal CT scanning has supplanted the contrast enema as the acute diagnostic procedure of choice and allows guided percutaneous drainage of large abscesses in selected cases. This approach helps realize the surgical ideal of a single elective operation without a temporary colostomy. For those patients still requiring emergency surgery, the two-stage approach employing resection of the diseased colon at the initial operation is far superior to the older three-stage approach. 