Fiber in the gastrointestinal tract.

It has long been recognized that fruit, vegetables, and cereal fiber alter bowel function. The right colon can be regarded as a fermenter and an absorbing organ, and the left colon is for continence. A rationale for the use of fiber based on physical chemical properties is discussed. On this basis, the use of coarse wheat bran, apples, oranges, and carrots is recommended to treat diverticular disease, spastic colon, and constipation.