Patients with diverticular disease should be categorized for therapeutic purposes into 3 groups: (1) asymptomatic diverticulosis (accidental finding; (2) painful diverticular disease (no inflammation); and (3) acute diverticulitis (pericolitis present). In asymptomatic diverticulosis a high-fiber diet should be given, and an operation is not indicated. In painful diverticular disease resection of the sigmoid colon should be considered after recurrent attacks. In acute diverticulitis resection should be performed after the second inflammatory attack. The younger the patient, the earlier an operation should be considered.