To define the general types and incidences of bowel disorders affecting the indigenous adult population of South Iran, a sample of clinical material over a four-year period was reviewed. While certain infectious diseases of the colon, notably amebiasis and less so tuberculosis, were expectedly common, chronic ulcerative colitis is seemingly nonexistent among the native population. An absence of diverticulosis contrasts with a high incidence of volvulus of various portions of the bowel, including the cecum. Cancer of the colon and rectum appears, for unknown reasons, to be relatively uncommon. Geographically-determined features of large-bowel disorders peculiar to this part of the world can be attributed to either clear-cut environmental forces or less distinct racial characteristics, but the relative roles of these forces are unknown. © 1969 American Proctologic Society.