5 Foods That Can Cause Diarrhea

And substitutes that may help ease symptoms

Certain foods can cause diarrhea either because they have a laxative effect and you've eaten too much or because they irritate the digestive tract. It is also possible that you have an intolerance to certain foods (like dairy) or are simply eating an imbalanced diet with too many fatty foods and not enough fiber.

Managing your intake of foods that trigger diarrhea is especially important if you are living with digestive disorders that cause diarrhea, such as inflammatory bowel disease (Crohn’s disease and ulcerative colitis). The same applies to irritable bowel syndrome (IBS), and most specifically the type known as diarrhea-predominant type (IBS-D).

This article looks at five foods that may be the culprit behind (or at least an accomplice to) your chronic diarrhea. It explains why they cause diarrhea and possible substitutes or solutions that may help ease loose or watery stools.



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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.

As with other forms of food intolerance, milk intolerance occurs when your body lacks the enzymes needed to break down lactose.

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

There are some over-the-counter products that can help with the digestion of milk sugar, most specifically lactose supplements. There are even milk products in which lactose has already been broken down, making them 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 that acts as an allergen.

Hot Peppers

hot pepper in a bottle

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

There is a substance called capsaicin in certain kinds of peppers (including jalapeño peppers and cayenne peppers) that can trigger diarrhea. It does so by irritating the lining of the intestines, which, in turn, speeds the movement of the intestines to "flush out" the offender.

In addition to diarrhea, abdominal cramps and rectal burning are common when too many spicy foods are consumed.

Interestingly, casein, a protein found in milk, can lessen the burning effect of capsaicin.


High angle view of coffee and tea sample cups

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Caffeine speeds up digestion and can have a laxative effect, particularly in people prone to diarrhea. While some people are more sensitive to caffeine than others, drinking excessive amounts of caffeine can cause loose stools in almost anyone.

Coffee, black teas, and colas are common sources of caffeine. Other, lesser-known sources include chocolate and energy drinks containing guarana.

Coffee and IBS

Coffee may induce a bowel movement in some people, but this is thought to be less related to the caffeine content and more to substances in coffee that influence the interaction between the brain and digestive tract (known as the brain-gut axis).​ In people with IBS, this effect can contribute to the onset of IBS symptoms, including diarrhea.

If you have a taste for coffee but are struggling with diarrhea, decaffeinated coffee is certainly an option. Or, you could try chicory coffee made from the root of the chicory plant.

Saturated or Trans Fats

Potato chips

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Fatty, greasy, or fried foods contain saturated fats and trans fats. They are also known as "solid fats" because they congeal and harden at room temperature. Because the body has trouble breaking down these fats, the oils pass through the digestive tract largely intact and cause diarrhea.

When saturated or trans fats are eaten in excess, you may even see a greasy streak in the toilet water surrounding a stool.

By reducing your intake of saturated fats to no more than 10% of your total daily calories, you may not only help ease diarrhea symptoms but also your heart health.

If you have chronic or severe diarrhea, you may need to reduce your intake even further, substituting saturated or trans fats for healthier polyunsaturated or monounsaturated fats found in olive, canola, peanut, sunflower, and safflower oils, as well as avocados, peanut butter, nuts, and lean cuts of chicken, pork, and beef.

Artificial Sweeteners

Artificial sweeteners

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Sugar substitutes such as sorbitol and mannitol can be found in a variety of foods, ranging from candies and sodas to yogurt and packet sweeteners. Even so-called "healthy" foods touted as "sugar-free" may contain these artificial sweeteners.

Artificial sweeteners are broken down at a slower rate than sugar and remain intact as they move through the digestive tract, drawing more and more water into the stool. As such, they act like an osmotic laxative much in the same way as Miralax (polyethylene glycol) and milk of magnesia

While sugar substitutes definitely have their benefits for people with diabetes and weight issues, the overconsumption of artificial sweeteners can contribute to the onset or worsening of diarrhea.

And, this is a problem since the U.S. Food and Drug Administration (FDA) recommends no more than 50 milligrams (mg) of artificial sweetener per day, and one can of diet cola delivers more than 200 mg.

If you want to avoid sugar but like sweet things, opt for a natural sweetener called Stevia made from the stevia plant. It's about 100 to 300 times sweeter than table sugar and less likely to cause diarrhea.

9 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.
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  9. Moran AW, Al-Rammahi MA, Daly K, et al. Consumption of a natural high-intensity sweetener enhances activity and expression of rabbit intestinal Na+/glucose cotransporter 1 (SGLT1) and improves colibacillosis-induced enteric disorders. J Agric Food Chem. 2020 Jan 15;68(2):441–50. doi:10.1021/acs.jafc.9b04995

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.