Irritable Bowel Syndrome Health Article

Definition

Irritable bowel syndrome (IBS) is a common gastrointestinal condition characterized by abdominal pain and cramps; changes in bowel movements (diarrhea, constipation, or both); gassiness; bloating; nausea; and other symptoms. There is no cure for IBS; however, dietary changes, stress management, and sometimes medications are often able to eliminate or substantially reduce its symptoms.

Description

IBS is the name people use today for a condition that was once called—among other things—spastic colitis, mucous colitis, spastic colon, nervous colon, spastic bowel, and functional bowel disorder. Some of these names reflected the now outdated belief that IBS is a purely psychological disorder, a product of the patient's imagination. Although modern medicine recognizes that stress, anxiety and depression can trigger IBS attacks, medical specialists agree that IBS is a genuine physical disorder—or group of disorders—with specific identifiable characteristics. IBS is considered a functional disorder because it is thought to result from changes in the activity of the major part of the large intestine (the colon).

Demographics

IBS is one of the most common functional gastrointestinal disorders, affecting 10-20 percent of adults in the United States. Research has demonstrated that symptoms compatible with IBS are about as common in school-age children as in adults. IBS normally makes its first appearance during young adulthood, and symptoms usually begin at about age 20. Women with IBS represent over 70 percent of IBS sufferers. IBS is responsible for more time lost from school and work than any medical problem—other than the common cold. It accounts for a substantial proportion of the patients seen by specialists in diseases of the digestive system (gastroenterologists).

A community-based study of 507 middle school and high school students by Hyams, et al, found that 6-14 percent of the adolescent population had IBS symptoms. Anxiety and depression scores were significantly higher for this group. Eight percent of all the students in the study had seen a physician for abdominal pain in the previous year.

Causes

Although the exact cause or causes of IBS are unknown, research suggests that people with IBS may have a colon that is more sensitive and reactive to certain foods and stress.

After food is digested by the stomach and small intestine, the undigested material passes in liquid form into the colon, which absorbs water, nutrients and salts. Normally, the colon is quiet during most of that period except after meals, when its muscles contract in a series of wavelike movements called peristalsis. Peristalsis helps absorption by bringing the undigested material into contact with the colon wall. It also pushes undigested material that has been converted into solid or semisolid feces toward the rectum, where it remains until a bowel movement occurs.

In IBS, however, the normal rhythm and intensity of peristalsis is disrupted. Sometimes there is too little peristalsis, which can slow the passage of undigested material through the colon and cause constipation. Sometimes there is too much, which has the opposite effect and causes diarrhea. In other cases, peristalsis can be spasmodic, causing sudden strong muscle contractions that come and go.

DIET Some foods and beverages appear to play a key role in triggering IBS attacks. Certain foods and drinks may disrupt peristalsis in IBS patients, which may explain why IBS attacks often occur shortly after meals. Some of the chief culprits include:

• chocolate
• dairy products
• caffeine (in coffee, tea, colas, and other drinks)
• carbonated beverages (colas, pop, soda)
• wheat
• rye
• barley
• excess alcohol

Other foods also have been identified as problems, and the pattern of what can and cannot be tolerated is different for each person.

STRESS Stress—feeling mentally or emotionally tense, troubled, angry or overwhelmed—stimulates colon spasms in people with IBS since there is a close nervous system connection between the brain and the intestines. A large network of nerves control the normal rhythmic contractions of the colon. Although researchers do not yet understand all of the links between changes in the nervous system and IBS, they point out the similarities between mild digestive upsets and IBS. Just as healthy people can feel nauseated or have an upset stomach when under stress, people with IBS react the same way, but to a greater degree.

MENSTRUATION IBS symptoms sometimes intensify during menstruation, suggesting female reproductive hormones may trigger the condition.