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Irritable bowel syndrome (IBS) is a common disorder of the intestines.

Common IBS symptoms include:

• Cramping.
• Stomach pain.
• Gas.
• Bloating.
• Changes in bowel habits.

Some people with IBS have constipation (infrequent bowel movements). Others have diarrhea (frequent, loose stools). Some people have both.

Eating more or less fiber can help control these problems.

Tips to Increase Fiber in Your Diet and Help Constipation

If you have constipation, a high-fiber diet can help. Foods high in soluble fibers — like oats, peas, and beans — can help ease both constipation and diarrhea.

Add fiber a little at a time

• Try to eat 20 to 35 grams of fiber each day. Use food labels to tell how many grams of fiber are in foods you eat.
• Add more fiber to your diet a little at a time. Adding too much fiber too quickly may trigger other IBS symptoms. Be sure to increase your fluid intake at the same time.
• Put more fiber in meat dishes by adding beans, bran, or oatmeal.
• Ask your doctor if a multivitamin and mineral supplement with 100% of the U.S. recommended daily intake (RDI) of fiber may be helpful.

RELATED: Understanding Indigestion: Causes, Symptoms, and Treatment

Watch for foods that cause your IBS symptoms

• Pay attention to when your symptoms occur. If you can relate these times with certain foods, avoid those foods.
• Keep a food diary.
• To help reduce gas, try an over-the counter pill like Beano®.

Drink plenty of fluids and eat slowly

• Drink at least 8 cups of fluid per day. Water is best, but fruit juice and decaf drinks also are fine.
• Eat more slowly. Take the time to chew and enjoy your food.
• Eat smaller, more frequent meals. For instance, eat 4 or 5 small meals instead of 3 large meals.

High-Fiber Foods to Relieve Constipation

Choose more fresh fruits and vegetables

Choose more whole-grain breads, pastas, and cereals

Look for:

• Breads and cereals that list whole-grain or whole-wheat first on the food label.
• Cooked and ready-to-eat cereals with at least 5 grams of fiber per serving.

Choose more dried beans, peas, nuts, and seeds (as tolerated)

Choose more snacks that are high in fiber

Plan more vegetarian meals

Tips to Control Diarrhea with a Low-Fiber Diet

During a flare-up of IBS, a low-fiber diet can help control diarrhea.

This means more cooked foods, fewer raw fruits and vegetables, and fewer bran-based grains, cereals, and breads.

Sometimes changing the number of meals you eat, choosing different foods, and adjusting food temperature can help relieve diarrhea.

Limit fat and dairy in your diet

• Add less fat to foods.
• Select baked foods instead of fried foods.
• Choose low-fat versions of foods and dairy products, such as cottage cheese and yogurt.
• Limit dairy products or use a lactase product.
• If you’re limiting dairy, ask your doctor if you should take a calcium supplement.

Eat smaller portions and drink more liquids

• Eat smaller portions.
• Don’t skip meals.
• Avoid very hot meals and caffeine which tend to cause diarrhea.
• Avoid foods that cause gas.
• Try to rest after meal to help slow the rate at which food passes through the intestines.
• Drink plenty of liquids between meals.
• Try drinking liquids at room temperature. Best choices are water, broth, nonacidic juices, nectars, and sport drinks.

Not all of these tips may work for everyone. If there’s something you haven’t tried, test it to see if it helps your diarrhea and other IBS symptoms.

Low-Fiber Foods to Choose and Avoid

Choose foods known to bind and help control diarrhea

Try other foods and products that may relieve diarrhea

Choose foods high in potassium

Diarrhea may rob the body of electrolytes (sodium and potassium), so make sure that you eat foods high in potassium such as:

Avoid foods and drinks that may cause diarrhea

Certain foods produce loose stools. You should avoid these if your IBS causes diarrhea.

Need More Help Controlling Your IBS Symptoms?

Visit the UPMC Digestive Disorders Center website for more information on managing constipation, diarrhea, and other IBS symptoms.

Editor's Note: This article was originally published on March 26, 2016, and was last reviewed on February 7, 2023.