Learning About the Low FODMAP Diet for Irritable Bowel Syndrome (IBS)

What is the low-FODMAP diet?

A low-FODMAP diet is used to find out if certain foods make irritable bowel syndrome (IBS) worse. You stop eating high-FODMAP foods for 2 to 6 weeks. Then you slowly add them back to see how your body reacts.

This is called an elimination diet. A dietitian or doctor can help you follow this diet.

FODMAPs are types of carbohydrates that can be hard for your body to digest. They are in many types of foods. FODMAP stands for:

  • F ermentable.
  • O ligosaccharides.
  • D isaccharides.
  • M onosaccharides.
  • A nd p olyols.

If you have IBS, foods that are high in FODMAPs may make your symptoms worse. When you are on this diet, you can still eat carbohydrates that are low in FODMAPs. This includes certain fruits, vegetables, grains, and low-lactose dairy products.

What is it used for?

This diet is used to help manage symptoms of irritable bowel syndrome (IBS). The diet limits foods that are high in FODMAPs.

High-FODMAP foods can be hard to digest. They pull more fluid into your intestines. They are also easily fermented. This can lead to bloating, belly pain, gas, and diarrhea.

The low-FODMAP diet can help you figure out what foods to avoid. And it can help you find foods that are easier to digest.

This diet can help with IBS symptoms. But it's not a cure. You will still need to manage your condition.

How does it work?

At first, you won't eat any high-FODMAP foods for a few weeks.

It can be helpful to work with a dietitian who is trained in the low-FODMAP diet when you try this diet. They can help you find recipes and FODMAP food lists to use while you are on the diet.

After 2 to 6 weeks, you will start to try high-FODMAP foods again. You will add those foods back to your diet, one at a time. Your doctor or dietitian will probably have you wait a few days before you add each new food.

Keep a food diary. You can write down the foods you try and note how they make you feel.

After a few weeks, you may have a better idea of what foods you should avoid and what foods you can eat without triggering IBS symptoms.

What are the risks?

There is some risk of not getting all of the vitamins and nutrients you need on the low-FODMAP diet. These include:

  • Folate.
  • Thiamin.
  • Vitamin B6.
  • Calcium.
  • Vitamin D.

Your dietitian or doctor can help you find other sources of these if needed.

This diet may limit your fiber intake. If you need more fiber, ask your doctor or dietitian about low-FODMAP fiber sources.

What foods are on the low-FODMAP diet?

Here is a guide to foods that you can eat, plus the foods that you should avoid, when you are on the low-FODMAP diet.

Grains

Okay to eat: Foods made from grains like arrowroot, buckwheat, cornmeal, millet, and oats. You can also eat potato flour, quinoa, rice, sorghum, tapioca, and teff. Cereals, pasta, breads, corn tortillas and baked goods made from these grains are also okay. (These grains may be labeled "gluten-free.")

Avoid: Grains like wheat, barley, and rye. Avoid ingredients such as bulgur, couscous, durum, and semolina. And avoid cereals, breads, and pastas made from these grains. Avoid chickpea, lentil, and pea flour.

Proteins

Okay to eat: Most meat, fish, and eggs without high-FODMAP sauces. You can have small amounts of almonds or hazelnuts (10 nuts). Macadamia nuts, peanuts, pecans, pine nuts, and walnuts are also okay. You can also eat chia and pumpkin seeds, tofu, and tempeh.

Avoid: Beans, chickpeas, lentils, and soybeans. Avoid pistachio and cashew nuts. Avoid fatty or fried meats. And some sausages may have high-FODMAP ingredients.

Dairy

Okay to eat: Lactose-free dairy milks. Rice milk and almond milk are okay. So are lactose-free yogurts, kefirs, ice creams, and sorbet from low-FODMAP fruits and sweeteners. (These are often labeled "lactose-free.") You can have small amounts (2 Tbsp) of cottage, cream, or ricotta cheese. Hard cheeses like cheddar, Colby, Parmesan, and Swiss are okay. So are small amounts (1 oz) of aged or ripened cheeses like Brie, blue, and feta.

Avoid: Milk, including cow, goat, and sheep. Avoid condensed or evaporated milk, buttermilk, custard, cream, sour cream, yogurt, and ice cream. Avoid soy milk. (Check sauces for dairy ingredients.)

Vegetables

Okay to eat: Bamboo shoots, bell peppers, bok choy, broccoli, cabbage (red or white), and cucumbers. Eggplant, green beans, lettuce, olives, parsnips, and potatoes are okay to eat. So are pumpkin, rutabaga, seaweed, sprouts, Swiss chard, and spinach. You can eat scallions (green part only) and yellow or spaghetti squash. You can eat tomatoes, turnips, watercress, yams, and zucchini. You can also have small amounts of artichoke hearts (from can, 1 oz), carrots, corn (½ cob), and sweet potato (½ cup).

Avoid: Artichokes, asparagus, Brussels sprouts, savoy cabbage, cauliflower, and celery. And avoid garlic, leeks, mushrooms, okra, onions, scallions (white part), shallots, and peas.

Fruits

Okay to eat: Bananas, blueberries, cantaloupe, grapes, and honeydew. Kiwi, lemons, limes, oranges, passion fruit, papaya, and pineapple are also okay. You can eat plantain, raspberries, rhubarb, star fruit, strawberries, tangelo, and tangerine. You can also have small amounts of dried banana chips (up to 10 chips), dried cranberries (1 Tbsp), and shredded coconut (up to ¼ cup).

Avoid: Apples, applesauce, apricots, avocados, blackberries, boysenberries, and cherries. Also avoid dates, figs, grapefruit, guava, lychee, and mangoes. Don't eat nectarines, peaches, pears, persimmon, plums, prunes, tamarillo, or watermelon. And limit most canned and dried fruits.

Oils, spices, condiments, and sweeteners

Okay to eat: Vegetable oils (including garlic infused), butter, ghee, lard, and margarine. You can have most fresh herbs like basil, chives, coriander, ginger, parsley, rosemary, and thyme. You can have salt, jams made from low-FODMAP fruits, mayonnaise, and mustard. Soy sauce, hot sauce (no garlic), tamari, and vinegar are also okay. Sweeteners that are okay include sugar (sucrose), powdered (confectioner's) sugar, brown sugar, glucose, and maple syrup. You can also have some artificial sweeteners like aspartame, saccharine, and stevia.

Avoid: Chutneys, hummus, jellies, garlic sauces, and gravies made with onion or garlic. Avoid pickles, relish, some salad dressings and soup stocks, salsa, and tomato paste. And avoid sauces and other foods with high fructose corn syrup, honey, molasses, and agave. Avoid artificial sweeteners (isomalt, mannitol, malitol, sorbitol, and xylitol). Avoid corn syrup solids, fructose, fruit juice concentrate, and polydextrose.

Other foods and drinks

Okay to have: Water, soda water, tonic, soft drinks sweetened with sugar, ½ cup of low-FODMAP fruit juice, and most teas and alcohols. You can also eat foods made with baking powder and soda, cocoa, and gelatin.

Avoid: Juices from high-FODMAP fruits and vegetables. And avoid fortified wines, chamomile and fennel teas, chicory-based drinks and coffee substitutes, and bouillon cubes.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.