Irritable bowel syndrome (IBS) is a common problem with the intestines. In people with IBS, the intestines squeeze too hard or not hard enough and cause food to move too quickly or too slowly through the intestines. IBS usually begins around age 20 and is more common in women.

IBS is also called functional bowel syndrome, irritable colon (the large intestine is also called the colon), spastic bowel and spastic colon. It's not the same as inflammatory bowel diseases like ulcerative colitis.

Your doctor may start by asking you questions about your symptoms. If your symptoms have had a pattern over time, the pattern may make it clear to your doctor that IBS is the cause.

If your symptoms have just started, something else may be the cause. Your doctor may need to do some tests, such as a blood test or colonoscopy, to make sure that your symptoms aren't caused by something other than IBS.

Fiber can be helpful because it improves how the intestines work. There are 2 types of fiber: soluble and insoluble. (Soluble means it dissolves in liquid.) Soluble fiber helps both diarrhea and constipation. Insoluble fiber may make diarrhea worse.

Insoluble fiber is in fruits, vegetables, whole grain breads and cereals. Psyllium (a natural vegetable fiber) and oat bran are soluble fibers. You can buy psyllium (some brand names: Fiberall, Metamucil, Perdiem) at the store. Oat bran is in some cereals, bread or muffins. You can also add it to other foods.

Increase the fiber in your diet slowly. Some people feel bloated and have gas if they increase their fiber intake too quickly. Gas and bloating usually improve as you get used to eating more fiber.

No. Foods don't cause IBS. But some foods may make you feel worse. Foods that may make symptoms worse include foods high in fat or caffeine. Fat and caffeine can cause your intestines to contract, which may cause cramping. Alcohol and chocolate may also make you feel worse. If gas is a problem for you, you might want to avoid foods that tend to make gas worse. These include beans, cabbage and some fruits.

Keeping a diary of what you eat and what your symptoms are for a few weeks may be a good way to find out if a food bothers you. If you think a food makes you feel worse, don't eat it. But don't cut out foods unless they have caused you problems more than once.

If milk and other dairy products bother you, you may have lactose intolerance. Lactose intolerance means that your body can't digest lactose (the sugar in milk).

Dairy products may seem to make IBS symptoms worse if you're lactose intolerant. If this seems to be the case, you may need to limit the amount of milk and milk products in your diet. Talk to your family doctor if you think you have trouble digesting dairy products.

There is no cure for IBS. However, if you're having bad symptoms, your doctor may prescribe medicine to help you manage or lessen your symptoms.

For example, antispasmodic medicines may be prescribed to reduce cramping if your main symptom is pain. Hyoscyamine (some brand names: Anaspaz, Cystospaz, Levsin) and dicyclomine (some brand names: Bentyl, Di-Spaz) help relax the spasms in the colon. Heating pads and hot baths can also be comforting.

When diarrhea is a frequent problem, medicine such as loperamide (brand name: Imodium) may help.

Your doctor may give you tranquilizers or sedatives for short periods to treat anxiety that may be making your symptoms worse. Your doctor may prescribe an antidepressant for you if your symptoms are severe and you are feeling depressed.