Inflammatory bowel disease in Cape Town, 1975-1980. Part II. Crohn's disease.

Patients with Crohn's disease seen in the Gastro-intestinal Clinic of Groote Schuur Hospital between 1975 and 1980 were studied to establish the incidence and clinical features of this disease. There were 117 patients and the mean (+/- SEM) follow-up was 6,1 +/- 0,5 years. Of these patients 72% were White, 37% Coloured and 1% Black. The incidence for the Coloured and White population groups was calculated to be 0,4 and 0,9/100 000 per year during 1970-1974 and 1,3 and 1,2/100 000 per year during 1975-1980 respectively. In Jews the rates were 5,0 and 7,2/100 000 per year for the two periods. Insufficient data are available to calculate an incidence for the Black population. The disease involved the ileum in 39%, the colon in 17% and both areas in 44% of patients. At presentation 18% of patients had mild, 37% moderate, and 45% severe disease. The severity of symptoms was not related to the extent of the disease. A peri-anal fistula was present in 24% of patients. There was no difference in clinical features between the different population groups. Surgical resection had been performed in 50% of patients and 29% of these had had two or more resections. The surgical rate in the ileitis group was 63%, in the ileocolitis group 49% and in those with colitis 20%.