Because of potential significance of bile acids and cholesterol metabolites in the pathogenesis of colon cancer, fecal neutral sterols, and bile acids were determined in patients with colon cancer, adenomatous polyps or other digestive diseases and American or Japanese controls. The fecal excretion of cholesterol, coprostanol, coprostanone, total bile acids, deoxycholic acid, lithocholic acid was higher in patients with colon cancer and patients with adenomatous polyps compared to normal American and Japanese controls as well as patients with other digestive diseases. Patients with other digestive diseases excreted comparable levels of fecal bile acids and cholesterol metabolites compared to normal American controls; Japanese controls excreted reduced levels compared to normal American controls. These findings suggest that possible interactions between bile acids and cholesterol metabolites and colonic epithelial cells may be relevant in colon carcinogenesis.