ABSTRACT
Large bowel cancer is one of the most common cancers in North America, northwestern Europe, Australia, and the river plate area of South America, but is rare in Africa, Asia, and the Andean countries of South and Central America. A mechanism for the development of colorectal cancer has been proposed which includes genetic and environmental factors. There is a large body of evidence implicating the bile acids in colorectal carcinogenesis which includes populations with a wide range of incidences of colorectal cancer, case-control studies, studies of patients with diseases which confer a high risk of colorectal cancer, and studies of animal models. Patients who have had a colorectal cancer removed successfully are at high risk of developing a subsequent primary carcinoma in the remaining colon. The carriage of nuclear dehydrogenating clostridia in the whole group of polyp patients, the nonadenomas, and the adenomas was very similar to that in the control patients.
