Introduction In most elderly patients with diverticular disease of the colon, a perforated diverticulum will wall off in the peritoneal cavity and form an abscess. With hospitalization and judicious use of antibiotics, an inflammatory mass will be formed at the site of perforation. Thickening and induration of the mesocolon and narrowing and angulation of the bowel will follow the perforation. Recognizing these pathologic changes, most patients may be treated conservatively, without a preliminary colostomy, and the inflammatory tumor resected at a one-stage surgical operation. Varying degrees of a colon obstruction may occur early in the period of hospitalization, but this can be relieved by nasogastric intubation, realizing that the obstruction is inflammatory, temporary, and responds to antibiotic therapy. In all cases the diagnosis is confirmed by x-ray studies of the colon, taking proper safeguards in the presence of a perforation and modifying the technique so as not to completely fill