Constipation is a condition in which bowel movements become infrequent and difficult. This condition can be caused by lack of fiber in the diet or by insufficient exercise. Constipation can be a symptom of serious intestinal disease and should be diagnosed by a physician if it persists.

OTC laxatives help relieve constipation. There are three types of laxatives: bulk, stimulant, and lubricant.

Bulk laxatives such as Citrucel or Fiberall are the most natural type of laxative. When taken after a meal, they pass through the stomach into the intestine. They are not absorbed into the body. While in the intestine, they draw water into the intestine. This softens the stool and increases its volume. The increased volume in the intestine triggers the contraction of intestinal muscles. The muscular contracting aids in the passage of fecal matter. If taken properly, bulk laxatives may be taken over an extended period of time.

Stimulant laxatives such as Dulcolax and Ex-Lax work on the nerve endings in the intestinal wall to stimulate muscular contraction. Muscular contraction propels the fecal matter through the large intestine. Extended use of stimulant laxatives may upset normal bowel movement.

Lubricant laxatives, commonly called stool softeners, are of little value for the long-term treatment of constipation. They are most useful for people with medical conditions that make it desirable to avoid straining at the stool. They are often combined with either bulk or stimulant laxatives, and should be taken for only a short period of time. Colace, Correctol, Feen-a-mint and Senokot-S are lubricant laxatives.