In Western communities diverticular disease occurs mainly in the sigmoid colon. This contrasts with Oriental populations, in which diverticula occur mainly in the right colon. Diverticular disease has recently emerged in black South Africans. This study shows that diverticula in this population occurs predominantly in the descending colon. The variable anatomic distribution of diverticula in different ethnic groups implies that fiber deficiency is not the only factor responsible for this condition. It is suggested that diverticular disease may comprise several entities with different causes.