The geography of chronic digestive disease in southern Africa.

Lifestyle and dietary patterns are in the process of rapid transformation in Soweto. Comparisons with whites indicate differences in bowel behaviour, lactase deficiency and breath methanes. The association between smoking pipe tobacco and cancer of the oesophagus is confirmed, but home-brew consumption has been found to be the major risk factor in this cancer. A recent swing to Western-type alcohol has led to the emergence of alcohol-induced pancreatitis in blacks. Urbanisation and westernisation have also affected the influence of the traditional healer and the incidence of duodenal ulcer disease. The fundamental environmental influence which determines non-infective large-bowel disease is diet. A dietary survey of Sowetans indicates that their present diet is low in fat and fibre. Despite the latter, appendicitis is still relatively uncommon. Other significant differences are observed in colorectal cancer and diverticular disease.