Diverticular disease of the colon: a deficiency disease of Western civilization.

We present a hypothesis as to the cause of diverticulosis coli which is consistent with its geographical distribution, its recent emergence as a medical problem, and its changing incidence. Diverticulosis appears to be a deficiency disease caused by the refining of carbohydrates which entails the removal of vegetable fibre from the diet. Consequently we consider it to be prevent- able.