Constipation is a disorder in which there is difficulty moving one's bowel. It is a fairly common problem, particularly for those living in the western hemisphere and for some people it can be chronic and worrisome. What is considered a "normal" bowel movement varies with the individual and geography. In the West, where diet tends to be low in roughage and fiber, stools tend to be low in weight; the normal number of bowel movements ranges from one movement twice a week or one or two movements a day. In rural Africa and other countries where grain is a dietary staple, movements are bulkier and much more frequent, as often as six or seven times a day. Not everyone can produce or needs a bowel movement every day. Most people miss a day now and then and don't even notice it. However, for those who have chronic difficulty, who must strain to produce a dry, hard bowel movement, constipation can be uncomfortable and painful. Constipation often produces a bloated feeling because the bowel distends with gas and liquid, as well as large amounts of stool in the colon.
The most common cause of constipation is insufficient fiber in the diet, but many other causes contribute to chronic constipation. People with inflammatory bowel disease may have constipation because the colon doesn't always contract properly. In others, the pressure in the anus is too high (anismus). Some medications may also cause constipation: iron supplements, antidepressant medications, painkillers and some medications for hypertension. People suffering from low thyroid (hypothyroidism) or en excess of calcium in the blood tend to suffer from constipation. So do pregnant women and people who are sedentary or confined to bed rest. Depression at times can cause constipation. Travelers almost universally complain of constipation on the first few days of a trip, although it is difficult to say why this is so. It may be a change in sleeping or eating habits or water intake, or sitting long hours while traveling. Some people have a cathartic colon, or "lazy bowel", decreased bowel contractions often caused excessive use of laxatives.
Some people develop constipation because they are too busy to move their bowels when they get the urge to defecate. Others may ignore the urge whenever they are outside their home. The longer the stool remains in the colon, the more water the colon reabsorbs. The stool gets smaller, firmer and thus more difficult to evacuate. Over time, this disregard for the urge to have a bowel movement can interfere with the normal pattern of bowel habits and require relearning of the conditioned deprecatory reflex.
Less commonly, constipation can occur when nerves to the bowel are severed during surgery. This can occur when some types of back surgery and after a hysterectomy. Bladder function may also be affected.
A word of caution about constipation: if you suffer from chronic constipation, it's important to have a check up to make sure no serious disease is present and that no underlying hormonal or electrolyte imbalance is causing the constipation. A recent change in bowel habits, especially a narrowing of stools, may signify colon cancer and also require a thorough evaluation. This is especially true when rectal bleeding is present. Any new onset of constipation, especially for those over the age of forty, should be evaluated by a physician.
