5 Foods That Can Cause Diarrhea

Healthy adults may have diarrhea several times a year, usually without knowing exactly what caused the problem. Many people may not realize that there are some foods that cause diarrhea.

People with inflammatory bowel disease (Crohn’s disease and ulcerative colitis) may have near constant diarrhea when the disease is active and inflammation is present in the intestinal tract.

People with irritable bowel syndrome (IBS), and especially those who have the diarrhea-predominant type (IBS-D) may also find that certain foods aggravate symptoms and cause loose stools.

For people who have very sensitive digestive systems, these foods may cause an episode of diarrhea, even without any other underlying disease or condition. If you are having diarrhea, avoiding the foods listed below could be helpful in lessening the severity, as well as how long the loose stools last.



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Lactose, the sugar that is found naturally in milk, can cause diarrhea in some people. This condition is called lactose intolerance, and it’s very common in people over the age of 2.

Symptoms of lactose intolerance can include gas, diarrhea, bloating, cramps, nausea, and very bad breath. Avoiding milk products is generally the way to prevent diarrhea caused by lactose intolerance.

There are, however, over-the-counter products that can help with the digestion of milk sugar. There are even milk products that have had the lactose in it already broken down, which makes it easier to digest.

Lactose intolerance is not the same as a true milk allergy. People with a milk allergy should avoid all milk products, even those that are lactose-free, because it is not the sugar in milk that causes an allergy, but the protein.

Hot Peppers

hot pepper in a bottle

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Hot peppers are a frequent offender, but they often don’t cause diarrhea until several hours after they are eaten. Because of this delay, some people might not make the connection.

There is a substance called capsaicin in certain kinds of peppers (including bell peppers, jalapeño peppers, cayenne peppers, and some chili peppers) that can trigger diarrhea. Capsaicin is also used in ointments that treat arthritis.

Interestingly, casein, which is a protein found in milk, can lessen the burning effect of capsaicin. Aside from the capsaicin, some people may find the seeds and skin of the pepper are also difficult to pass.


High angle view of coffee and tea sample cups

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Caffeine speeds up the body systems, including digestion. Some people are more sensitive to caffeine than others, but too much caffeine can lead to diarrhea.

Coffee, tea, and soda are common places to find caffeine. Other, lesser-known caffeine sources include chocolate, gum, and even some flavors of bottled water.

Coffee may make some people have a bowel movement, but this is thought to be less related to the caffeine content and more from other substances coffee contains.​

Artificial Fat

Potato chips

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Olestra, a fat substitute, has become well known for its association with “anal leakage” and diarrhea, which are problems that people would like to avoid. Olestra passes through the body without being absorbed

While the Food And Drug Administration concluded that effects from olestra are “infrequent“ and “mild,” people with sensitive digestive tracts may still experience diarrhea after eating it.

Olestra can be found in many products (most famously potato chips), especially those that are marketed as “light,” “low fat,” or “fat-free.”

Sugar Substitutes

Artificial sweeteners

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Sugar substitutes such as sorbitol and mannitol can be found in a variety of foods, everything from candy to yogurt. Even so-called healthy foods which are often touted as "sugar-free" may contain these additives, so reading nutrition labels on foods is going to be the key to avoiding them.

Many of these sweeteners can be found in natural sources also, such as fruit and vegetables. Foods that contain these types of sugars may be high on the FODMAP scale.

FODMAPs are fermentable oligo-, di- and mono-saccharides, and polyols, and limiting them may be helpful for some people with digestive problems, namely IBS. They cause gas and bloating because they are not well absorbed by the intestine.

These food additives cause extra water to get pulled in to the bowel, which can cause stools to be looser. In addition, bacteria in the bowel eat these sugars and produce even more gas.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institutes of Health Genetics Home Reference. Lactose intolerance.

  2. Esmaillzadeh A, Keshteli AH, Hajishafiee M, Feizi A, Feinle-Bisset C, Adibi P. Consumption of spicy foods and the prevalence of irritable bowel syndrome. World J Gastroenterol. 2013;19(38):6465–6471. doi: 10.3748/wjg.v19.i38.6465

  3. Brown SR, Cann PA, Read NW. Effect of coffee on distal colon function. Gut. 1990;31(4):450–453. doi: 10.1136/gut.31.4.450

  4. U.S. Food and Drug Administration. Food additives permitted for direct addition to food for human consumption; Olestra. Federal Register. Document number 03-19508. August 5, 2003.

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.