Javascript is not enabled.

Javascript must be enabled to use this site. Please enable Javascript in your browser and try again.

Skip to content
Content starts here
CLOSE ×
Search
Leaving AARP.org Website

You are now leaving AARP.org and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

The Diet for Irritable Bowel Syndrome

Foods to eat and to avoid when trying the FODMAP diet, plus tips for how to get started


spinner image collage of meats, fruits and dairy
AARP (Source: Getty Images)

If you’re living with the uncomfortable symptoms of irritable bowel syndrome (IBS), you’re not alone. The American College of Gastroenterology estimates that 10 to 15 percent of adults in the United States live with IBS.

IBS is a common intestinal disorder affecting the gastrointestinal tract. Symptoms include constipation, gas, diarrhea, stomach pain and bloating. Many people with IBS have found relief in a diet designed to reduce their symptoms. Called the low-FODMAP diet, it’s an eating pattern that reduces and limits types of carbohydrates that can be hard for people to digest.

In a 2021 analysis of studies on the use of the FODMAP diet for IBS, researchers found that it reduces symptoms by a moderate to large extent and improves quality of life.

“About 50 to 80 percent of people can improve or better manage their gut symptoms using the FODMAP diet,” says Emily Haller, a gastrointestinal dietitian, lifestyle and culinary medicine program coordinator and team member at Trinity Health Ann Arbor. Haller works with IBS patients to reduce symptoms by using the FODMAP diet.

Tips for starting a low-FODMAP diet

  1. Speak with your doctor before beginning a dietary program.
  2. Enlist the help of a qualified registered dietitian who has experience in the FODMAP diet.
  3. Prepare before starting. Block out time in your schedule for grocery shopping, cooking and rest.
  4. Keep a food journal. Listen to your body, and record changes in symptoms.
  5. Share your journey with a trusted friend or family member who can support and encourage you.

During the first phase of the diet, typically lasting two to six weeks, a patient eliminates high-FODMAP foods under the care of a registered dietitian with experience in GI issues. During this initial phase, the patient can observe whether removing these foods helps to reduce IBS symptoms. If so, phase two begins.

Phase two of the diet slowly reintroduces high-FODMAP foods systematically to test and recognize trigger foods.

The third phase creates a sustainable lifestyle combining low-FODMAP foods and nontriggering high-FODMAP foods the individual can tolerate. “There’s no benefit to avoiding FODMAPs if they’re not your trigger,” Haller says.

What is the FODMAP diet?

FODMAP is a group of fermentable, short-chain carbohydrates that some individuals with IBS, or irritable bowel syndrome, have difficulty digesting. The lack of specific enzymes in the small intestine can be why some people with IBS have difficulty digesting these foods.

The full name for the diet is a tongue-twisting list of those carbohydrates: fermentable oligosaccharides, disaccharides, monosaccharides and polyols — or the acronym FODMAP.

“These plant foods are all very nutrient-dense,” Haller says. “But they most certainly can be problematic for somebody with IBS.”

Fermentable foods are broken down by yeast or bacteria in our gut converting them into gases. This process is called fermentation. When the gas passes into the large intestine, it can cause pain and discomfort.

Oligosaccharides are prebiotic fibers from soluble plants, which beneficial bacteria in our gut feed on. However, these fibers can exacerbate symptoms for someone with IBS. Onions, garlic, beans, lentils, bananas, some nuts and wheat are all oligosaccharides.

Disaccharides are fermentable sugars found in lactose. Lactose intolerance is common and stems from an insufficient enzyme called lactase in the digestive system. According to the American College of Gastroenterology, 15 percent of adult Caucasians and 85 percent of adult African Americans have difficulty digesting lactose. Individuals of Asian, Hispanic or Native American descent and those of Jewish heritage also have high rates of lactose intolerance.

Monosaccharides are simple sugars commonly found in honey, fresh and dried fruit, processed breakfast cereals, sauces and flavored yogurts.

Polyols are in some fruits and vegetables. Examples are cauliflower, shiitake mushrooms, snow peas, apples, plums and watermelon. Artificial sweeteners such as sorbitol, mannitol, isomalt and xylitol contain polyols.

What foods trigger IBS?

Common IBS-trigger foods are gluten, lactose-containing dairy products, processed foods and alcohol.

Everyone has a unique microbiome and responds to food differently. The three-phase elimination process of the FODMAP diet will help you recognize which foods trigger your IBS symptoms.

What are the highest-FODMAP foods?

Vegetables

  • Onions
  • Garlic
  • Cauliflower
  • Cabbage
  • Mushrooms
  • Peas

Fruit

  • Apples
  • Blackberries
  • Cherries
  • Mango
  • Peaches
  • Pears
  • Prunes
  • Watermelon

Meat

  • Processed meats

Grains

  • Barley
  • Rye
  • Spelt
  • Wheat

Nuts

  • Cashews
  • Pistachios

Milk

  • Cow milk
  • Goat milk
  • Sheep milk

What foods are allowed on the FODMAP diet?

During phase one of the diet, you eliminate all high-FODMAP foods. Rest assured, there are plenty of low-FODMAP foods you can freely enjoy. 

Examples of low-FODMAP foods include:  

Vegetables

  • Broccoli
  • Bell peppers
  • Carrots
  • Celery
  • Corn
  • Cucumber
  • Eggplant
  • Kale
  • Lettuce
  • Potatoes
  • Sweet potatoes
  • Tomatoes

Fruit

  • Bananas
  • Clementines
  • Grapes
  • Honeydew melon
  • Lemons
  • Oranges
  • Pineapple
  • Strawberries

Meat

  • Beef
  • Chicken
  • Lamb
  • Pork

Grains

  • Oats
  • Quinoa
  • Gluten-free breads, pasta, crackers, etc.
  • Popcorn
  • Rice
  • Cornmeal

Nuts and seeds

  • Chestnuts
  • Macadamia nuts
  • Peanuts
  • Pumpkin seeds
  • Sesame seeds
  • Walnuts

Milk, dairy and eggs

  • Almond milk
  • Eggs
  • Brie
  • Cheddar
  • Cottage cheese
  • Feta
  • Hemp milk
  • Oat milk
  • Lactose-free milk
  • Parmesan
  • Swiss

Can you lose weight on the FODMAP diet?

Weight loss is not the primary goal of going on the FODMAP diet; it is to help improve IBS symptoms. However, some people may lose weight because the low-FODMAP diet is based on whole foods.

If your doctor recommends losing weight alongside reducing IBS symptoms, speak with your dietitian, who can ensure you get enough nutrients.

What are negatives of the low FODMAP diet?

1. It can be overwhelming at first.

Many common foods, including onions, apples and honey, are high-FODMAP, so the diet can feel restrictive. However, moving through the three phases of the FODMAP diet over a few months may offer more dietary options for someone with IBS, not less.

“People with IBS are already restricting their diet — because food hurts. They’re already not eating a well-balanced diet,” Haller says. “When somebody comes in and they’re eating five, six foods or skipping meals because they don’t want to have an upset stomach at church on Sunday or at work, we’re able to help them expand their diet, which is really always a major goal of what we do.”

2. It may be more expensive.

Specific diets, including the low-FODMAP plan, can cost more if they include gluten- and dairy-free replacement foods. Almond milk yogurt is more expensive than cow’s milk yogurt. Gluten-free flour is more costly than wheat flour.

Conversely, on the diet, you’ll remove higher-priced grocery items, including alcoholic drinks, highly processed snacks and soda. This can make room in your grocery budget for pricey substitutions.

3. Eating in social situations can be challenging.

Eliminating or reducing commonly enjoyed foods can be extra challenging when eating out. Wait until phase three of the FODMAP diet if possible. You’ll best understand what you can eat and what to avoid. In time, you may be able to enjoy small amounts of FODMAP foods that previously triggered IBS symptoms.

Unlock Access to AARP Members Edition

Join AARP to Continue

Already a Member?