Perforation of the sigmoid colon simulating acute appendicitis.

Diverticulitis and carcinoma with abscess formation following perforation of the redundant sigmoid colon was erroneously diagnosed as acute appendicitis in nine patients over a period of five years. As te inflammatory process develops in the right lower quadrant of the abdomen, lack of previous colonic pathology may lead to a misdiagnosis, usually of acute appendicitis. It should be borne in mind, however, that acute appendicitis decreases with age, whereas diverticula and carcinomas increase, and that the sigmoid colon is often a redundant organ with a tendency to migrate to the right side of the abdomen. In elderly patients with acute right abdominal pathology, it is important to operate through a transrectal or paramedian incision. A two-stage operation is preferable to a three-stage one.