The function of the large intestine, also known as the large bowel or colon, is to absorb water and pass waste to the rectum, where it is stored until it is expelled. By the time fecal material reaches the rectum, most of the water is gone and the stool is fairly solid. If the fecal mass lacks bulk from fibrous foods, it can move too slowly through the colon. Too much water is absorbed by the colon and the stool becomes hard and dry. If the material passes through the colon too quickly, loose watery stools or diarrhea result.
Preventative treatment begins with a diet that keeps the stool soft, bulky, and easy to pass.
Foods with a high content of fiber retain water, increase bulk, and lubricate the fecal mass. Without necessary bulk, the colon may not be able to push the waste material through properly. Foods high in fiber are raw or whole fruits and vegetables, including skin and pulp, whole grain cereals, whole grain bread, and bran. Bowel habits can be learned by taking an early cup of coffee or tea into the bathroom, shutting the door, and relaxing a few minutes whether you have a bowel movement or not. Excessive straining can cause irritation and hemorrhoids.