Ask Dr. K: Ways to improve symptoms of IBS

Q: I have irritable bowel syndrome with alternating constipation and diarrhea. Will eating more fiber help? What about probiotics or other nonmedical treatments?

A: Irritable bowel syndrome (IBS) is a common intestinal disorder with many unpleasant symptoms. Many people with IBS go back and forth between diarrhea and constipation, with pain and bloating in between. Others always have diarrhea or constipation.

Unfortunately, there is no cure for IBS. However, there are a number of things you can do to improve your symptoms.

Adding fiber to your diet can help relieve constipation. Fiber increases the stool's bulk and speeds its movement through the gastrointestinal tract. It may also ease abdominal pain, and even improve diarrhea.

You can increase the fiber in your diet by eating whole grains, bran cereals and plenty of fresh fruits and vegetables. You can also try a fiber supplement containing psyllium or methyl cellulose.

When introducing fiber to your diet, do so gradually. Too much, too fast can cause excessive gas, cramping and bloating. Drink lots of water or other liquids. And be aware that for some people, a high-fiber diet may increase bloating or gas. I speak from both professional and personal experience.

You also asked about probiotics. That means we need to talk about bacteria. The world, including our bodies, is filled with bacteria. Some are good for us, some bad, some neutral. Probiotics are living bacteria that we swallow in order to improve our health. They come in the form of capsules, yogurts and even some fruit juices.

Probiotics are generally considered safe, but there's not yet enough evidence to say that they effectively treat IBS. Some of my patients swear by them; others have not had a positive result. No one has had any bad reactions.

For some people with IBS, certain foods can trigger symptoms. In particular, certain sugarlike molecules, known as FODMAPS, can be difficult to digest. FODMAPs are found in a wide variety of foods including milk, some fruits and vegetables, wheat, rye, high-fructose corn syrup and artificial sweeteners. A low-FODMAP diet may tame IBS symptoms.

IBS symptoms are also often triggered by emotional stress. The following stress-management techniques may help:

• Cognitive Behavioral Therapy (CBT). CBT can help reframe negative thoughts into more positive, productive ways of thinking. This can help to improve symptoms and quality of life.

• Relaxation Response Training and Meditation. These techniques help reduce nervous system activity (the intestines are partly controlled by the nervous system) and relax muscles.

• Yoga. This discipline seeks to bring body and mind into balance. It can serve as a form of self-relaxation.

• Biofeedback. Biofeedback is a mind-body technique. Participants use a biofeedback machine to see and learn to control their body's response to pain.

Fiber and probiotics definitely help many people with IBS. Fortunately, they are not the only treatments. And you'll notice I didn't even mention conventional medicines, since more "natural" approaches often do the trick.

• Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.