Irritable bowel syndrome

Update of Patient Note originally published in November 1995.

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Frequent stomach cramps, bloating, and diarrhea or constipation with passing of mucus. This collection of symptoms used to be called a nervous stomach or a spastic colon, but now we know it by the more descriptive name of irritable bowel syndrome, or IBS. One of the most common reasons people visit the doctor, IBS affects about one in five persons in the United States and can occur in children as well as adults.

What is IBS?
It is a group of uncomfortable--and sometimes disabling--symptoms that affect the large intestine, or colon. The abdominal pain, spasms, gas, and bloating can range from mild to so severe that the person can't work.

Women are two to three times more likely than men to have this condition, which usually begins around age 20 years. The good news is that IBS does not indicate damage to the colon or lead to bleeding or any other serious disease such as cancer.

What causes IBS?
No one knows exactly why some people have a more sensitive colon than others. However, it appears that certain foods and stressful situations trigger the symptoms.

In a healthy colon, food moves along through a series of gentle contractions. In IBS, the colon contractions are not regular. The diarrhea and bowel urgency associated with IBS are thought to be caused by the colon moving food too quickly, overwhelming the ability of the colon lining to absorb the fluid passing through. As a result, there is too much fluid in the stool. The constipation is believed to be caused by the colon moving food too slowly, giving the colon lining too much time to absorb fluid that normally keeps the stool soft.

How is it diagnosed?
A doctor uses a physical examination and a history of symptoms to help rule out conditions that may have symptoms similar to those of IBS, such as inflammatory bowel disease (ulcerative colitis and Crohn's disease) and lactose intolerance. Fever, weight loss, blood in the stool, and persistent severe pain are not associated with IBS and may indicate a more serious problem. Diagnostic tests, such as an x-ray, blood tests, or endoscopy (visualization of the colon using a flexible tube passed through the rectum and into the colon), may be performed.

For symptoms to be diagnosed as IBS, the abdominal pain must have been present for at least 12 weeks out of the last year. The pain also must be relieved by having a bowel movement, and the bowel movement must either look different than normal or come more or less often than usual.

How is IBS treated?
There is no cure, but symptoms of IBS can usually be controlled through diet and stress management. Under the guidance of a physician or dietitian, foods that commonly irritate the colon, such as wheat, rye, barley, chocolate, and dairy products, usually are eliminated from the diet one by one to see if symptoms disappear. If symptoms don't disappear and the food doesn't seem to be responsible for symptoms, it can gradually be reintroduced into the diet.

Drinking six to eight glasses of water daily and eating high-fiber, low-fat foods (for example, fruits, vegetables, and whole-grain breads and cereals) are recommended. Drinking carbonated beverages, alcohol, and caffeinated beverages; eating high-fat and spicy foods; and smoking are discouraged. Some foods, such as beans, cabbage, and cauliflower, naturally produce gas and should be limited or avoided. Meals that are small, regular, and frequent are encouraged because they are easier to digest than large ones.

Stress-reduction techniques, such as meditation, biofeedback, cognitive behavior therapy, and yoga or other exercise, may also help reduce the severity and frequency of symptoms.

If such efforts aren't effective, medications or supplements may be prescribed. Drugs that are sometimes used include fiber supplements, laxatives, antidiarrheal medicines, medications used to calm colon spasms, and antidepressants.

Symptoms of IBS usually come and go over a lifetime, and what helps one person may not help another. It may take some time to find out what works for you, but once you do, it will be easier to prevent and manage attacks when they do occur.

For more information on irritable bowel syndrome International Foundation for Functional Gastrointestinal Disorders PO Box 170864 Milwaukee, WI 53217 888-964-2001 http://www.iffgd.org National Digestive Diseases Information Clearinghouse National Institutes of Health 2 Information Way Bethesda, MD 20892 http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/index.shtml and http://digestive.niddk.nih.gov/ddiseases/pubs/ibschildren.shtml

This information is not a substitute for medical treatment.