Burkitt is usually credited with popularizing the potential relationship between intake of dietary fiber and colorectal cancer. Despite the controversies surrounding colon cancer and dietary fiber, the hypothesis that dietary fiber protects against colon cancer remains plausible and attractive. Dietary fiber is not an accurate term because many of its components are not fibrous. Gums and mucilages, for example, are classified as dietary fiber because they are not digested by mammalian enzymes or secretions. The difficulty in devising a method for assessing total dietary fiber can be appreciated if one considers the diverse nature of dietary fiber. Dietary fiber affects the digestive tract from mouth to anus and has other important physiological functions. Dietary treatments have been tested as chemopreventive measures in the process of colorectal cancer. Studies on dietary fiber and colon cancer are also severely limited because of problems in defining, measuring, and quantitating dietary fiber.