A healthful diet means eating a wide variety of nutritious foods. However, people with irritable bowel syndrome (IBS) may notice that certain foods trigger uncomfortable digestive symptoms.

The specific foods that trigger IBS are different for different people, so it’s not possible to draw up a single list of foods to avoid.

That said, many people will notice that avoiding some of the most common triggers — including dairy, alcohol, and fried foods — results in:

  • more regular bowel movements
  • fewer cramps
  • less bloating

Keep reading to find out which foods could be making your IBS more uncomfortable.

Dietary fiber adds bulk to the diet and, generally speaking, it helps keep the gut healthy. Foods that are high in fiber include:

  • whole grains
  • vegetables
  • fruits

There are two types of fiber found in foods:

  • insoluble
  • soluble

Most plant foods contain both insoluble and soluble fiber, but some foods 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.

Soluble fiber is a great choice for most people with IBS. The American College of Gastroenterology (ACG) recommend taking soluble fiber supplements, such as psyllium, as a cheap, effective treatment for IBS.

On the other hand, they say that insoluble fiber, such as wheat bran, may make pain and bloating worse.

Fiber tolerance is different for different people. Foods rich in insoluble fiber may worsen symptoms in some people, but others with IBS have no issues with these foods. Additionally, some foods high in soluble fiber, like beans, can cause issues for some people who have IBS.

As you can see, diet and IBS is highly individualized and certain fiber-rich foods may not agree with you while others may improve symptoms.

If foods like this cause symptoms, try taking soluble fiber supplements instead.

Gluten is a group of proteins found in grains including rye, wheat, and barley, which may cause problems for some people with IBS.

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

Celiac disease is an autoimmune disorder. It affects the intestinal cells, resulting in poor absorption of nutrients. The causes of gluten intolerance, or non-celiac gluten sensitivity, are less well-defined.

Research suggests that a gluten-free diet can improve IBS symptoms in around half of people studied, per a 2015 study.

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

The good news is that more and more gluten-free products are coming onto the market at a fast pace. If you can’t do without pizza, pasta, cakes, or cookies, you can always substitute them with gluten-free options.

What’s more, there are many whole, nutritious alternatives to gluten- containing grains and flours available including:

  • quinoa
  • sorghum
  • oats
  • buckwheat
  • almond flour
  • coconut flour

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

First, many types of dairy are high in fat, which can lead to diarrhea. Switching to low fat or nonfat dairy may reduce your symptoms.

Second, many people with IBS report that milk is a trigger for their symptoms, though it’s unclear if people with IBS are more likely to have true lactose intolerance.

If you feel that dairy or milk products are causing uncomfortable digestive problems, consider switching to dairy alternatives, such as plant milks and soy-based cheese.

If you need to cut out dairy completely, focus on consuming other calcium-rich foods like:

  • greens
  • beans
  • nuts
  • sardines
  • seeds

Choosing calcium-rich foods is recommended over calcium supplements because supplements may do more harm than good in most cases, as outlined in a 2017 study.

French fries and other fried foods are common in the typical Western diet. However, eating too much can cause health problems. The high fat content may be especially hard on the system for people with IBS.

Frying food can actually change the chemical makeup of the food, making it more difficult to digest, which leads to uncomfortable digestive symptoms.

For a more healthful option, try grilling or baking your favorite foods instead.

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:

  • gas
  • bloating
  • cramps

Try avoiding beans to see if this helps with your IBS symptoms. Or, when eating beans or lentils, soaking them overnight and then rinsing them before cooking can help the body digest them more easily.

Some people swear by their morning coffee for digestive regularity. But like all caffeinated drinks, coffee has a stimulating effect on the intestines that can cause diarrhea.

Coffee, sodas, and energy drinks that contain caffeine can be triggers for people with IBS.

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

Processed foods tend to contain a lot of:

  • added salt
  • sugar
  • fat

Examples of processed foods include:

  • chips
  • premade frozen meals
  • processed meats
  • deep-fried foods

Eating too much of these ingredients 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 4 servings of ultra-processed foods per day was linked a higher risk of developing IBS, along with:

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

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

Sugar-free sweeteners are common in:

  • sugarless candy
  • gum
  • most diet drinks
  • mouthwash

Commonly used sugar substitutes include:

  • sugar alcohols
  • artificial sweeteners
  • natural zero-calorie sweeteners like stevia

Artificial sweeteners, which can have negative effects on health, can contain ingredients like:

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

  • gas
  • digestive discomfort
  • laxative effects

Common sugar alcohols that may cause IBS symptoms include:

  • sorbitol
  • mannitol

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

Chocolate bars and chocolate candy can trigger IBS because they’re typically high in fat and sugar and commonly contain lactose and caffeine. Some people experience constipation after eating chocolate.

There are some vegan options for chocolate lovers that people with IBS often find to be more tolerable.

Alcoholic drinks are a common trigger for people with IBS. This is because of the way the body digests alcohol. Also, alcohol can lead to dehydration, which can affect digestion.

Beer is an especially risky option because it often contains gluten, and wines and mixed drinks can contain high amounts of sugar.

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

Garlic and onions are great flavoring agents in your food, but they can also be difficult for your intestines to break down, which causes gas.

Painful gas and cramping can result from raw garlic and onions, and even cooked versions of these foods can be triggers.

Broccoli and cauliflower are difficult for the body to digest — which is why they may trigger symptoms in those with IBS.

When your intestine breaks these foods down, it causes gas, and at times, constipation, even for people without IBS.

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

Many doctors recommend that people with IBS follow the low FODMAP diet. This diet focuses on limiting foods rich in certain types of carbohydrates.

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharaides, and polyols. These are fermentable, short-chain carbohydrates.

According to Harvard Medical School, research suggests that the small intestine cannot easily absorb foods that contain FODMAPs. They may cause bloating, gas, and stomach pain.

Foods that contain FODMAPS 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, mannitol, and xylitol

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

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

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

Other healthful low FODMAP foods that you can enjoy include:

  • lactose-free dairy products
  • some fruits, including bananas, blueberries, grapes, kiwi, 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

The low FODMAP diet involves elimination and reintroduction phases and is difficult to follow without the help of a healthcare provider.

If you’re interested in trying out the low FODMAP diet, talk to a healthcare provider trained in digestive conditions such as a registered dietitian.

It’s important to remember that everyone’s digestion and food triggers are different. Some people with IBS can tolerate foods that others cannot.

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

Keeping a food and symptom diary can help you figure out 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.