CONSTIPATION

The purpose of the gastrointestinal (GI) tract is to extract fluid and essential nutrients from the food we eat and to eliminate wastes. All the way along the tract, food is propelled by involuntary rhythmic muscular contractions called peristalsis. From the mouth, ingested food proceeds down a straight tube called the esophagus into the stomach. It is here that the process of digestion begins, with stomach acid being secreted to break down food. Enzymes that also facilitate the breakdown of chemicals in food, permitting absorption into the bloodstream, are secreted here and in subsequent sections of the GI tract. From the stomach, food passes into the small intestine, a relatively thin, long (12 feet) tube with three distinct portions: duodenum, jejunum, and ileum. Enzymes from the pancreas and the gallbladder enter at the duodenum and have specific roles in the digestion of food. Generally, several hours later, the remaining food passes from the ileum into the large intestine or colon. The appendix is a pouch of uncertain function close to the junction between the large and small intestines. Water and some remaining nutrients are extracted in the large intestine, before the remains are excreted through the rectum as stool. 

Most of the time, the GI tract functions without problems, but there are a number of ways in which the system can go awry. Constipation is a significant change or persistent abnormality in bowel habits, usually with fewer than three stools per week, lumpy or hard stools, excessive straining, or incomplete emptying of the rectum. Causes include diet, body structure, complications of childbirth, a longer time for passage of intestinal contents, and certain medications. The latter include antacids, anticholinergics, antihistamines, antidepressants,  antipsychotics, benzodiazepines[1], diuretics, incontinence drugs, iron, and narcotics.[2] Constipation is more common in women, children, and older people. A rare condition called Hirschsprung’s disease also causes constipation, is more likely to affect males, and has onset in childhood.[3] Risk factors for constipation include anal fissures, cystic fibrosis, depression, diabetes, physical abuse, eating disorders, malabsorption disorders, multiple sclerosis, Parkinson’s disease, and pregnancy.[1],[2],[3],[4]

When do you really need to take a laxative? You should not take a laxative to “clean out your system” or to make your body act more “normally.” It is untrue that everyone must have a bowel movement daily. Perfectly healthy people may have from three bowel movements per week to three bowel movements per day.

If the frequency of your bowel movements has decreased, if you are having bowel movements less than three times a week, or if you are having difficulty passing stools, you are constipated, but this does not necessarily mean that you need a laxative. It is better to treat simple, occasional constipation without drugs, by eating a high-fiber diet that includes whole-grain breads and cereals, raw vegetables, raw and dried fruits, and beans, and by drinking plenty of nonalcoholic liquids (six to eight glasses per day). This type of diet will both prevent and treat constipation, and it is less costly than taking drugs. Regular exercise—at least 30 minutes per day of swimming, cycling, jogging, or brisk walking—will also help your body maintain regularity.

If you are constipated while traveling or at some other time when it is hard for you to eat properly, it may be appropriate to take a laxative for a short time. The only types of laxatives you should use for self-medication are bulk-forming laxatives such as psyllium or methycellulose (CITRUCEL), or a hyperosmotic laxative such as lactulose (CEPHULAC, CHRONOLAC). Bulk-forming laxatives usually take effect in 12 hours to three days, compared with docusate (COLACE, SURFAK), which takes effect one or two days after the first dose but may require three to five days of treatment. Even bulk-forming laxatives should only be used occasionally, if possible.