Course and prognosis of idiopathic ulcerative proctosigmoiditis in young patients.

The course and prognosis of idiopathic ulcerative proctosigmoiditis were studied in 85 young patients whose symptoms had begun before the age of 21 (mean age at onset, 16 years), and the results were compared with those in adults with proctosigmoiditis. Data regarding extension of disease, available in 66 patients, allowed us to identify two groups of patients. Presenting symptoms were the same in both groups. In Group I (41 patients, 62%), the disease remained stable or did not extend beyond the descending colon. In Group II (25 patients, 38%), there was evidence of extension to the hepatic flexure or beyond. Extension was unpredictable in individual patients, but generally occurred within 5 years from the onset of symptoms (73%). The clinical course and prognosis were different in each group. In Group I, there were more females, the disease ran a milder course, and there were few complications. In Group II, there were relatively more males, the disease was more active and severe, and a high incidence of intestinal and extraintestinal complications was observed. Fifteen patients, all from Group II, required colectomy. The natural history of proctosigmoiditis in young patients is somewhat different from that in adults, being characterized by a greater tendency to proximal extension (38% vs. 10%). However, when the disease remains confined to the rectosigmoid region (or does not spread beyond the splenic flexure), the course and prognosis are no different than in adults.