Ulcerative colitis is a type of inflammatory bowel disease that can cause intense periods of abdominal discomfort, diarrhea, and a loss of appetite. A person can manage it by eating or avoiding certain foods that can help reduce the risk of flares and inflammation.

There is no single diet for people with ulcerative colitis, but finding out and eliminating the foods that trigger symptoms can help reduce discomfort.

Doctors do not know the exact cause of this disease but think it has links to environmental factors, westernized diets and lifestyles, and genetics. Healthful diet management can help a person manage ulcerative colitis.

In this article, we explore which foods may trigger ulcerative colitis. It also looks at which foods might be beneficial for people with this form of inflammatory bowel disease (IBD).

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A person’s diet may contain a wide range of potential triggers, so it can be difficult for a person with ulcerative colitis to know what is safe to eat.

Some nutrients, such as fiber, may be hard for a person to digest during a flare. They may be able to eat other foods outside of a flare but find they cause discomfort while they are experiencing symptoms.

Foods that trigger symptoms will vary from person to person. People with ulcerative colitis must eat foods that provide a significant amount of potassium, folate, magnesium, calcium, and iron.

Some of the better food choices for someone with ulcerative colitis include:

  • Applesauce: This is a good source of nutrients. However, applesauce’s high fiber and fructose content may make it hard to digest during a flare.
  • Salmon: Salmon provides plenty of omega-3 fatty acids, which may have health benefits beyond the digestive tract.
  • Squash: Many varieties are high in fiber, which may make them a bad choice for some people during flares. However, some people with ulcerative colitis seem to tolerate squash well.
  • Avocados: These are rich in nutrients and healthful fats.
  • Some fermented foods: These include yogurts, containing active probiotics. The “good” bacteria in these can aid digestion. Some studies have shown routine use of probiotics can help reduce flares and symptoms.
  • Instant oatmeal: Instant oatmeal with no additional flavoring is slightly easier to digest than other forms of grains and oats.
  • Refined grains: It is best to eat pasta, bread, and cereal made from refined grains. Whole grains are harder to digest. Manufacturers enrich many white breads and grain products with extra minerals and vitamins.
  • Eggs: These offer several essential nutrients, including omega-3 supplementation. They are typically easy to digest, which makes them good for an ulcerative colitis diet plan.
  • Plenty of fluid: People with conditions such as ulcerative colitis may need to drink extra fluids, as diarrhea can lead to dehydration.

The foods people choose seem to have an impact on when flares of symptoms occur.

Diets will vary from person to person because not all people will respond the same way to a particular food.

Medical professionals recognize some foods as potential triggers for ulcerative colitis. These include:

  • Caffeine: Although there is not a lot of data on the effect of caffeine on ulcerative colitis symptoms, a 2013 survey of 442 people found that 22% of individuals with the condition reported caffeine made symptoms worse. Caffeine is a component of coffee, tea, soda, and chocolate.
  • Dairy products: While these are not problematic for all people with ulcerative colitis, dairy products can trigger symptoms in some individuals. People who also have lactose intolerance should avoid dairy, as the symptoms are similar.
  • Alcohol: This may trigger diarrhea in some people.
  • Carbonated drinks: Some sodas and beers contain carbonation that can irritate the digestive tract and cause gas. Many carbonated beverages also contain sugar, caffeine, or artificial sweeteners, which can also trigger symptoms.
  • High-fiber foods: These include dried beans, fruits, whole grains, berries, peas, and legumes. They may increase the number of bowel movements, the amount of gas, and abdominal cramping.
  • Popcorn: This can be difficult to digest, similarly to other seeds and nuts.
  • Potatoes: These contain glycoalkaloids, which may disrupt the cell membrane integrity of the gut. These occur in fried potato skins and chips more than baked or boiled potatoes.
  • Foods that contain sulfur or sulfites: This mineral can make a person produce excess gas. Some of these foods include beer, wine, almonds, cider, soy, wheat pasta, breads, peanuts, raisins, and cured meats.
  • Fatty meat: During a flare, the gut may not absorb fat from meat fully, which may make symptoms worse.
  • Nuts, nut butter, and seeds: They may cause abdominal cramping, bloating, and diarrhea. When a person experiences a flare, even small seeds may trigger symptoms.
  • Sugar alcohols: These can cause bloating, diarrhea, and gas. Manufacturers use sugar alcohol as a sweetener in many sugar-free gums and candies, some fruit juices, and various ice creams.
  • Fructose sugar: The body does not absorb higher amounts of fructose well, which can cause increased gas, cramping, and diarrhea. Check the label for ingredients such as high-fructose corn syrup, fruit juice, honey, and molasses, as these all contain fructose.
  • Many vegetables: These are often high in fiber, which can be hard to digest during a flare, causing bloating, gas, and abdominal cramps. Stringy vegetables, such as celery, are similar. Other gas-producing vegetables include cabbage, Brussels sprouts, and broccoli. People with ulcerative colitis tend to tolerate cooked vegetables better than raw ones.
  • Spicy foods: These include buffalo wings, hot sauces, and hot peppers. They may cause diarrhea in many people. For people with ulcerative colitis, hot and spicy foods may trigger or worsen a flare.
  • Gluten: This is a component of wheat, rye, and barley. It can sometimes trigger symptoms in ulcerative colitis. Although oats do not contain gluten, they have a similar protein that can cross-react in individuals who are sensitive to gluten. Manufacturers often also process oats in the same factory space as wheat.
  • Dietary emulsifiers: These include carboxymethylcellulose and polysorbate-80, which manufacturers add to many processed foods and can exacerbate symptoms.

For more science-backed resources on nutrition, visit our dedicated hub.

The best approach for people with ulcerative colitis to determine which foods to eat or avoid is by keeping a food journal.

A daily food journal allows a person with ulcerative colitis to make informed decisions about potentially harmful foods. They should organize it so that it is easy to read and share with a doctor. Some useful information to include would be:

  • the date
  • which foods a person ate, including a list of extras, such as sauces
  • the time of day at which a person ate the food
  • any immediate reactions
  • any flares or worsening symptoms

Food journals are particularly helpful when people are looking to add additional types of food to their diets.

By adding one food at a time and recording it, a person can determine whether the food is a safe choice or not by assessing whether symptoms are getting worse or staying the same.

Diet plans for people with ulcerative colitis will vary. The best tend to start with a food journal, which shapes the food choices and ideas in the plan.

Diet plans should include the following information:

  • Foods to eat: This will consist of foods a person knows will not aggravate their symptoms.
  • Foods to avoid: A diet plan should also list the specific foods that are known triggers.
  • Balanced nutrition: One of the most significant complications for people with ulcerative colitis is inadequate nutrition due to limited food tolerances. People should look for ways to modify foods rather than avoiding them so that they do not lose their nutritional benefits. For example, peeling or cooking a fruit or vegetable might make it more tolerable.
  • Supplements: Some otherwise healthful foods that are high in nutrients may not be digestible for some people. A person may need to compensate for this shortfall in nutrition. In these cases, an individual can take supplements to replace nutrients they cannot get in their food. Speak with a registered dietitian or doctor about which supplements may be best, and individual needs will vary.
  • Meal plans: These should take into account a person’s schedule and include snacks. The better the planning of a meal, the more likely it becomes that a person will stick to eating foods that do not aggravate their symptoms.
  • Review and approval of a doctor, dietitian, or nutritionist: It is a good idea to seek medical consultation, as professionals can offer advice on balancing the diet or suggesting alternative food choices that an individual might not have considered.
  • Continue the food journal: People should continue keeping a log even when they have a diet plan. Ulcerative colitis symptoms can change over time, so it is essential to track and record food intake to maintain the diet plan.

People should review diet plans occasionally to account for any changes in the body’s reaction to specific foods. It is also vital to inform a doctor if the flares start occurring more often or getting worse due to different foods.

There are some pre-made diets and plans available to help people. Some examples include diets that avoid foods that contain certain fermentable carbohydrates, such as the low FODMAP diet, which are low in residue or low in fiber.

However, diets for ulcerative colitis that claim to be “one size fits all” may not be suitable for everyone. Anyone looking to switch diets or follow a pre-made plan must talk with their doctor or dietitian before starting.

Having a support network consisting of experienced doctors and other health professionals is vital when living with ulcerative colitis. IBD Healthline is a free app for people living with ulcerative colitis. The app is available on the AppStore and Google Play. Download it here.


Can ulcerative colitis progress to a worse health condition if I eat the wrong thing?


Lifestyle factors that include consuming red meat and alcohol and overeating protein and sulfur-rich foods can increase the risk of a flare-up of ulcerative colitis.

This can worsen the condition and cause unpleasant symptoms. In addition, the risk of colon cancer increases significantly in those with ulcerative colitis, particularly if they are not managing it well.

It is important to improve diet, lower stress, and stay hydrated to improve the outcomes of an ulcerative colitis diagnosis.

Natalie Olsen, R.D., L.D., ACSM EP-C Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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