A retrospective study of the incidence and prevalence of paediatric inflammatory bowel disease over an 11 year period was undertaken in South Glamorgan. Over this time the incidence of Crohn's disease more than doubled from 1. 30 cases per 100,000 childhood population per year in the period 1983-1988, to 3. 11 cases per 100,000 population per year in the period 1989-1993. In contrast, the incidence of ulcerative colitis remained the same throughout the study period at 0 VSports手机版. 71 per 100,000 per year. In 1993 the prevalence of Crohn's disease in the childhood population was 16. 6 per 100,000 and of ulcerative colitis, 3. 42 per 100,000. .