Stercoral perforation of the colon is reported to be a rare disease with poor prognosis. The aim of this study was to determine the frequency of stercoral perforation of the colon, to define diagnostic criteria for stercoral perforation of the colon, and to analyze the patient outcome in a university hospital gastrointestinal surgery unit. From November 1993 until November 1998 all surgically treated patients with a colorectal disease were prospectively recorded in a computerized database. Diagnosis of stercoral perforation of the colon was made if 1) the colonic perforation was round or ovoid, exceeded 1 cm in diameter, and lay antimesenteric; 2) fecalomas were present within the colon, protruding through the perforation site or lying within the abdominal cavity; and 3) pressure necrosis or ulcer and chronic inflammatory reaction around the perforation site were present microscopically. Any additional colon pathology led to exclusion from the diagnosis of stercoral perforation of the colon. Using the same criteria, 81 cases in the literature were found to qualify and were further analyzed. In a five-year period 1,295 patients underwent colorectal interventions through laparotomy. A total of 566 (44 percent) cases were emergencies, 220 (17 percent) of these caused by colonic perforation. Seven patients had stercoral perforation of the colon. The incidence of stercoral perforation of the colon was 0.5 percent of all surgical colorectal procedures through laparotomy, 1.2 percent of all emergency colorectal procedures, and 3.2 percent of all colonic perforations. The mean age of the patients was 59 (median, 64; range, 22-85) years. All perforations were situated in the left hemicolon or upper rectum. The round or ovoid perforation had a mean diameter of 3.6 cm. Fecalomas were present in all patients and protruded from the perforation site or were found within the free abdominal cavity in three of them. Generalized stercoral peritonitis was a constant finding. Using a colonic resection without immediate restoration of continuity, an extensive intraoperative lavage, and antibiotics, there was no in-hospital mortality. Analysis of the reports in the literature revealed additionally that 28 percent of patients with stercoral perforation of the colon have multiple stercoral ulcers in the colon and that substantial mortality is encountered if only minor surgical procedures of treatment are used. The incidence of stercoral perforation of the colon seemed to have been underestimated. The reason for this might be the lack of defined diagnostic criteria for this disease. Low mortality is obtained by early surgical eradication of the affected part of the colon, including all stercoral ulcers, and by aggressive therapy for peritonitis.