WHAT FATE FOR ACUTE UNCLASSIFIED COLITIS - RESULTS OF A COHORT STUDY OF 104 CASES IN NORTHERN FRANCE

Acute unclassified colitis could be the first attack of inflammatory b owel disease, particulary chronic ulcerative colitis or acute non spec ific colitis regarded as being of infectious origin without recurrence . The aim of this work was to determine the outcome of 104 incidental cases of acute unclassified colitis diagnosed during the year 1988 at a census point made 2.5 to 3 years later and to search for demographic and clinical discriminating data for final diagnosis. Thirteen patien ts (12.5 %) were lost to follow up. Another final diagnosis was made i n three other patients: two had salmonellosis and one diverticulosis. Of the remaining 88 patients, 46 (52.3 %) relapsed and were subsequent ly classified as inflammatory bowel disease: 54 % ulcerative colitis, 33 % Crohn's disease and 13 % chronic unclassified colitis. Forty-two (47.7 %) did not relapse and were considered to have acute non specifi c colitis. The mean age at onset was significantly lower in patients w ith inflammatory bowel disease (32.3 years) than in patients with acut e non specific colitis (42.6 years) (P < 0.001). No clinical data (dia rrhea, abdominal pain, bloody stool, mucus discharge fever, weight los s) was predictive of the final diagnosis. In this series, 52.3 % of pa tients initially classified as having an acute unclassified colitis ha d a final diagnosis of inflammatory bowel disease after a 2.5-3 years follow-up. These data warrant a thorough follow up of acute unclassifi ed colitis, especially when it occurs in patients < 40 years.