Despite its frequency, ulcerative proctosigmoiditis is poorly recognized and its prognosis is not well understood. This study reviews experience at the Cleveland Clinic from 1960 through 1972, with a 97% follow-up. A total of 359 patients with a diagnosis of ulcerative proctosigmoiditis were followed for a mean of 11 years (range 3.2–17.7 years). There were 219 men and 140 women.
Mean age at diagnosis was 40.6 years. All had rectal bleeding, typical proctosigmoidoscopic findings of diffuse granularity, mucosal ulcerations and friability, and normal findings above the rectosigmoid on barium enema. The major complaint in all patients was rectal bleeding, and there were few other symptoms. Perianal disease was absent.
On the whole, the patients were older than the usual patients with ulcerative colitis; 37 were older than age 61 at diagnosis. The disease remained localized and the prognosis accordingly was good for 90% of the patients. Extension to the proximal colon developed in 10% (36) of patients, and operation was required in 8% (29), two for toxic megacolon. Operation was carried out a mean of 5.6 years after diagnosis: 2.2% (8) of the patients died during the period of follow-up, six after operation. One patient had carcinoma of the sigmoid colon 12 years after diagnosis. Only one patient was subsequently found to have Crohn's disease. Thirty-nine patients died from causes unrelated to colitis.
This study suggests that ulcerative proctosigmoiditis as defined by typical sigmoidoscopic appearance and a normal barium enema is relatively common, that proctosigmoidoscopic findings are identical with those of universal ulcerative colitis, but that the outlook is much better. Ulcerative proctosigmoiditis is rarely confused with Crohn's disease, and carcinoma is rare. Recurrences do occur, however, and proximal extension develops in 10% of patients, usually within 5 years after the diagnosis is first made.