12 Foods to Avoid with IBS

Dietary fiber adds bulk to the diet and generally helps keep the gut healthy. Most plant foods contain insoluble and soluble fiber, but some are high in one type.

• Soluble fiber is concentrated in beans, fruits, and oat products.
• Insoluble fiber is concentrated in whole grain products and vegetables.

Fiber tolerance can vary. Foods rich in insoluble fiber may worsen IBS symptoms in some people, but others may not have symptoms from these foods.

Foods high in soluble fiber may improve symptoms in many people with IBS but can cause issues for others. The American College of Gastroenterology (ACG) recommends taking fiber supplements, such as psyllium, as an affordable and effective treatment for IBS.

Gluten is a group of proteins found in grains that include:

• rye
• wheat
• barley

Some people’s bodies have a severe immune reaction to gluten, known as celiac disease. Others may have a gluten intolerance. These conditions share symptoms with diarrhea-predominant IBS.

A small study from 2022 suggests that a gluten-free diet can improve IBS symptoms in a significant number of people studied, though the mechanism is unclear. Another small study from 2022 found that following a gluten-free diet improved pain frequency and severity.

Some doctors recommend that people with IBS avoid gluten to see if their symptoms improve. If gluten worsens your symptoms, you may want to try a gluten-free diet.

Whole grain alternatives can include gluten-free grains like millet and quinoa.

Oats are often processed in gluten-containing facilities, which increases the chance of cross-contamination with gluten. If you’re extremely sensitive to gluten, you can look for products that specify on the packaging that they’re processed in a gluten-free facility.

Dairy may cause problems in people with IBS for several reasons.

First, high fat dairy can lead to diarrhea. Choosing low fat or nonfat dairy may help reduce your symptoms.

Second, many people with IBS report that milk triggers their symptoms. But it’s unclear if people with IBS are more likely to have lactose intolerance.

If eating dairy causes you digestive problems, consider switching to lactose-free milk and dairy alternatives, such as plant-based milk and soy-based cheese. Some people may find relief by taking lactase enzymes when eating dairy. There are also some naturally lactose-free cheeses, such as some varieties of sharp cheddar.

If you need to cut out dairy completely, you may need to get calcium from other calcium-rich foods.

Doctors may recommend choosing calcium-rich foods over calcium supplements, as supplements may increase your risk for cardiovascular conditions, as outlined in a 2017 study.

Fried foods have a high fat content that may be hard on the digestive system for people with IBS.

Frying food can change the chemical makeup of particular food, making it more difficult to digest. Eating fried foods can lead to uncomfortable digestive symptoms and even cause health problems.

Try grilling, baking, or air-frying your favorite foods for a more healthful option.

Beans, lentils, and peas are generally a great source of protein and fiber, but they can cause IBS symptoms. They contain compounds called oligosaccharides that are resistant to digestion by intestinal enzymes.

While beans can increase bulk in stool to help constipation, they also increase IBS symptoms.

You may want to try avoiding beans to see if it helps. Or you can try soaking dried beans or lentils overnight and rinsing them thoroughly before cooking to help the body digest them more easily.

Caffeinated drinks, including coffee, have a stimulating effect on the intestines and can cause diarrhea. Caffeine-containing coffee, sodas, and energy drinks can be triggers for people with IBS.

If you need an energy boost or pick-me-up, consider eating a small snack or taking a quick walk instead.

Highly processed foods typically contain substances you would not use to prepare food at home. This includes:

• added salt
• sugar
• fat
• additives

Examples of highly processed foods can include:

• chips
• premade frozen meals
• processed meats like hot dogs and fish sticks
• deep-fried foods
• sweetened breakfast cereals
• sugary beverages
• energy and protein bars with added sugars

Eating too much of these foods can lead to health problems for anyone. In addition, they often contain additives or preservatives that might trigger IBS flare-ups.

A 2019 review found that eating four servings of ultra-processed foods per day was linked to a higher risk of developing IBS, along with:

• cancer
• obesity
• high blood pressure

When possible, making meals at home or buying fresh produce is a healthful alternative to highly processed foods.

Sugar-free doesn’t mean it’s good for your health — especially when it comes to IBS.

In the place of sugar, many sugar-free foods contain sugar-free sweeteners. Common ones can include:

• sugar alcohols, such as sorbitol and mannitol
• artificial sweeteners, such as sucralose, acesulfame potassium, and aspartame
• natural zero-calorie sweeteners like stevia

Research also shows that sugar alcohols are hard for the body to absorb, especially in people with IBS, causing:

• gas
• digestive discomfort
• laxative effects

Artificial sweeteners may negatively affect the gut microbiome and increase inflammation, according to 2021 research.

Reading the ingredient labels of any sugar-free products can help you avoid these compounds.

Chocolate bars and candy can trigger IBS due to their fat and sugar content. They also commonly contain lactose and caffeine. Some people experience constipation after eating chocolate.

Some vegan options for chocolate lovers may be more tolerable for people with IBS.

Alcohol is a common trigger for people with IBS because of how the body digests it. Also, drinking alcohol can lead to dehydration, which affects digestion.

Beer may cause additional harmful effects because it often contains gluten.

Wines and mixed drinks can contain high amounts of sugar.

Limiting alcoholic beverages may help reduce symptoms related to IBS. If you drink alcohol, consider a gluten-free beer or a drink mixed with plain seltzer without artificial sweeteners or added sugar.

Garlic and onions can add flavor to food, but they contain fructans, an oligosaccharide, which can be difficult for your intestines to break down. This may cause gas.

Painful gas and cramping can result from raw garlic and onions. Even cooked versions of these foods can be triggers for some people with IBS.

Cruciferous vegetables are also difficult for the body to digest and may trigger IBS symptoms. This can include:

• broccoli
• cauliflower
• cabbage
• Brussels sprouts

When your digestive system breaks these foods down, it causes gas and constipation. These vegetables may even cause these symptoms in people who don’t have IBS.

Cooking vegetables makes them easier to digest, so consider roasting or sautéing broccoli and cauliflower if eating them raw bothers your digestive system.

Some doctors recommend that people with IBS follow the low FODMAP diet.

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are fermentable, short-chain carbohydrates. A low FODMAP diet limits foods rich in these carbohydrates.

Research suggests the small intestine cannot easily absorb foods containing FODMAPs. They may cause digestive symptoms.

Foods that contain FODMAPS can include:

• most dairy products
• some fruits, including apples, cherries, and mango
• some vegetables, including beans, lentils, cabbage, and cauliflower
• wheat and rye
• high fructose corn syrup
• sweeteners, such as sorbitol, maltitol, and xylitol

While avoiding the foods above, you can still enjoy a huge range of foods with low FODMAP scores.

For starters, foods that don’t contain carbohydrates or are low in FODMAPS are allowed in this diet. This can include:

• fish and other meats
• eggs
• butter and oils
• hard cheeses

Other healthful low-FODMAP foods that you can enjoy may include:

• lactose-free dairy products
• some fruits, including bananas, blueberries, grapes, kiwis, oranges, and pineapple
• some vegetables, including carrots, celery, eggplant, green beans, kale, pumpkin, spinach, and potato
• quinoa, rice, millet, and cornmeal
• firm and medium tofu
• pumpkin seeds, sesame seeds, and sunflower seeds

But eating a large serving of low FODMAP foods may still provide a large amount of FODMAPs.

The low FODMAP diet involves elimination and reintroduction phases and may be difficult to follow without the help of a healthcare professional. Not everyone with IBS is sensitive to all FODMAPs.

If you want to try out the low FODMAP diet, talk with a healthcare professional trained in digestive conditions, such as a registered dietitian or gastroenterologist.

The following includes frequently asked questions about IBS and diet.

What foods irritate IBS the most?

Fried foods and foods high in fat can be harder for the body to digest. In people with IBS, they may cause uncomfortable side effects like gas, bloating, and diarrhea.

What foods help settle IBS?

If you have IBS diarrhea, staying hydrated and eating foods that are gentle on the stomach and easy to digest may help. If you have IBS constipation, stay hydrated and try foods that may help move things along, like prunes or peaches.

What triggers IBS flare-ups?

Certain ingredients and drinks can trigger IBS symptoms. But these triggers can vary from person to person. Some common ones include artificial sugars, gluten, fried foods, alcohol, and other foods that may be hard to digest. Lifestyle factors like stress or gastrointestinal illnesses can also trigger an IBS flare-up.

Everyone’s digestion and food triggers are different. Some people with IBS can tolerate foods that others cannot.

Get to know your body, learn which foods make you feel the best, and limit those that cause uncomfortable symptoms.

Keeping a food and symptom diary can help you determine which foods to eat and avoid.

If you need extra help with your diet in relation to IBS, scheduling an appointment with a registered dietitian is a good choice.