The smooth muscular walls of the colon contract to move waste through it. This takes anywhere from 12-24 hours or longer, depending greatly on the amount of roughage present. Colon and rectal disorders are much more common in American than in Africa, where the diet contains seven times more fiber than the average Western diet. The colon works best when moderately full, and the dietary fiber fills this need. Although fiber provides no nutrients to the body, it does help promote good health because it is able to remove certain toxic materials along with many times its weight in water, which is needed to help maintain bowel regularity.
Insufficient roughage leads to constipation or, at the other extreme, diarrhea.
These ailments can also be caused by nervous stress. Intestinal problems common to the Western culture are often solved by the addition of fiber to the diet. High-fiber foods include bran, prunes, Psyllium seed or hulls and other mucilaginous herbs. When the colon is nutritionally supported with a diet high in natural fiber, other nutritional components and healthy bacteria, it is able to function at peak efficiency. Another factor in colon health is maintaining a good supply of beneficial bacteria such as lactobacillus acidophilus.