The stomach churns and mixes food so it can be digested. The near-liquid food then enters the small intestine, which extracts calories, minerals and vitamins. The small intestine ends in the right-lower abdomen where it enters the colon. The colon, or large bowel, is 5 to 6 feet long. Its function is to withdraw water from the liquid stool, so that by the time it reaches the rectum there is a soft-formed stool.
As water and waste materials enter your colon, or large intestine, the colon absorbs excess water while forming the waste products. Muscle contractions move the waste to the rectum. When the colon’s natural contractions are disturbed, waste materials move slowly. A lazy colon that does not contract properly and fails to move the stool to the rectum often causes constipation. The colon also can become spastic and remain contracted for a prolonged time. In this case, stool cannot move along. Too much water is absorbed and hard pellet-like stool. If an excessive amount of water is extracted, the stool can become hard and difficult to expel.
Constipation also can result from a mechanical obstruction, such as tumors or advanced Diverticulosis, a disorder, which can distort and narrow the lower-left colon. Other conditions that can produce a sluggish, poorly contracting bowel include: pregnancy, anal fissures and hemorrhoids, certain drugs, thyroid hormone deficiency, the abuse of laxatives, travel, and stress.