Am Fam Physician. 2010;82(12):1449-1451
What is irritable bowel syndrome?
Irritable bowel syndrome (IBS) is a common problem with the intestines. The cause is unknown, but it may have to do with the movement of the intestines, sensitivity of the intestine to pain or nerve signals, or changes in the bacteria that live in the gut. IBS usually begins around age 20 and is more common in women.
IBS is also called functional bowel syndrome, irritable colon, spastic bowel, and spastic colon. It's not the same as inflammatory bowel diseases like ulcerative colitis.
What are the symptoms of IBS?
Bloating and gas
Mucus in the stool
Diarrhea, especially after eating or first thing in the morning
Feeling a strong urge to have a bowel movement
Feeling like you still need to have a bowel movement after you've already had one
Stomach pain and cramping that may go away after having a bowel movement
The symptoms may get worse when you're under stress, such as when you travel, attend social events, or change your daily routine. Your symptoms may also get worse if you don't eat enough healthy foods or after you've eaten a big meal. Some people are bothered by certain foods. Women who have IBS may notice more frequent symptoms during their periods.
How is IBS diagnosed?
Your doctor may start by ruling out other illnesses. He or she will ask 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, your doctor may need to do some tests to make sure that your symptoms aren't caused by something other than IBS.
How is IBS treated?
The best way to manage IBS is to eat a healthy diet, avoid foods that make you feel worse, and find ways to cope with stress.
Why may fiber be helpful?
It can be helpful because it improves how the intestines work. There are two types of fiber:
Soluble fiber helps relieve diarrhea and constipation. It dissolves in water and forms a gel-like material. Many foods contain soluble fiber, such as apples, beans, and citrus fruits. Psyllium, a natural vegetable fiber, is also a soluble fiber. You can buy psyllium supplements (some brand names: Fiberall, Metamucil) to drink, and you can add it to other foods.
Insoluble fiber helps relieve constipation by moving material through your intestines and adding bulk to your stool. But this type of fiber can also make your symptoms worse. Insoluble fiber is in whole-grain breads, wheat bran, and many vegetables.
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. The best way to increase your fiber intake is to eat a variety of high-fiber foods.
Do certain foods cause IBS?
No. Foods don't cause IBS. But some foods may make you feel worse. 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, 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. Don't cut out foods unless they have caused you problems more than once.
What about milk and milk products?
If milk and other dairy products bother you, you may have lactose intolerance. This means that your body can't digest lactose (the sugar in milk).
Dairy products may make IBS symptoms worse if you're lactose intolerant. If this is the case, you may need to limit the amount of milk and milk products you eat. Talk to your doctor if you think you have trouble digesting dairy products.
How can stress affect IBS?
Stress may trigger IBS. Talk to your doctor about ways to cope with stress, such as exercise or talking to a counselor.
Can my doctor prescribe medicine for IBS?
There is no cure for IBS. 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 problem, medicine such as loperamide (brand name: Imodium) may help.
Will IBS get worse over time?
No. IBS will probably recur throughout your life, but it won't get worse. It doesn't cause cancer or require surgery, and it won't shorten your life.
What if IBS interferes with my daily activities?
IBS may have caused you to avoid doing certain things, like going out or going to work or school. It may take some time, but you may find new freedom by following a plan that includes a healthy diet, learning new ways to cope with stress, and avoiding foods that make your symptoms worse.
Tips on controlling IBS
Eat a varied healthy diet and avoid foods high in fat.
Drink plenty of water.
Try eating six small meals a day rather than three larger ones.
Learn new and better ways to cope with stress.
Avoid using laxatives. They may weaken your intestines and cause you to be dependent on them.