Diarrhea can often be the result of intestinal infections, a side effect of some medications — like antibiotics or magnesium-containing drugs — or a symptom of an underlying medical condition. However, certain foods can also leave you running to the bathroom a lot.
In fact, your diarrhea could be food-related if you've recently changed your diet or notice that it is only triggered by particular foods. Here are some foods that can cause excessive bowel movements.
Read more: Foods to Eat to Stop Diarrhea
1. Sugar and Sweeteners
Eating too much sugar can cause excessive bowel movements. Simply put, sugars travel from the small intestine into the bloodstream by various transporters, explains Lindsey Albenberg, DO, spokesperson of the American Gastroenterological Association and an attending physician in the Division of Pediatric Gastroenterology, Hepatology and Nutrition at the Children's Hospital of Philadelphia.
"When the transporters are overwhelmed, the sugars travel through the intestinal tract unabsorbed. And along the way, liquid follows the sugars and is drawn into the intestinal tube leading to more liquid stools, or diarrhea," says Dr. Albenberg.
Fructose — a sugar that is found in fruits, fruit juices, honey and in processed foods in the form of high-fructose corn syrup — can also cause loose stools for people with difficulty digesting it, according to the Mayo Clinic.
But don't just reach for artificial sweeteners as a replacement: Additives like sorbitol, mannitol and xylitol that are common in sugar-free candy and gum may cause also diarrhea in many, per the National Institute of Diabetes and Digestive and Kidney Diseases.
If that's the case for you, check the ingredient list for these sugar alternatives (known as sugar alcohols or polyols), which typically have names that end in "ol." You'll also often see a "sugar alcohol" section under total carbohydrates on the nutrition facts label, according to the FDA.
2. Insoluble Fiber
The FDA recommends 25 grams of dietary fiber a day for someone following a 2,000-calorie diet. Most Americans don't get enough fiber, but eating too much fiber or suddenly increasing your intake may cause digestive problems like gas, bloating and diarrhea.
There are two kinds of fiber — soluble and insoluble — and while both are important for healthy digestion, they're believed to have somewhat different effects when it comes to excessive bowel movements. "It is thought that soluble fiber can absorb water and add bulk to the stool, making it useful in the treatment of both constipation or diarrhea," Dr. Albenberg explains. Insoluble fiber, on the other hand, is believed to draw additional water into the colon, she says — making it useful for treating constipation, but not necessarily helpful for diarrhea.
According to Dr. Albenberg, foods high in soluble fiber that might improve symptoms of diarrhea include dried beans and peas, peanuts, lentils, sweet potatoes, carrots, berries, broccoli, bananas, apples, barley and rye.
3. Fatty Foods
Some people find that eating a meal high in fatty, greasy food gives them diarrhea. While fats are usually well-absorbed, "nearly every food in very high quantities can cause diarrhea likely because of the body's inability to keep up with digestion and absorption," says Dr. Albenberg. If the fat isn't absorbed adequately, it can cause the intestine to secrete more fluid. "Additionally, high-fat diets can upset the gut microbiota," she notes.
So if you've recently switched to a high-fat diet like keto — which often also lacks in fiber — that may be to blame for your digestive issues.
Read more: 6 Reasons the Keto Diet Is NOT for You
4. Milk and Dairy Products
Lactose intolerance is a common cause of loose stools and diarrhea, according to the Mayo Clinic. People with lactose intolerance lack the enzyme needed to digest lactose, the sugar found in milk and dairy products, and can experience symptoms like abdominal pain, bloating and diarrhea when they eat or drink it.
While some people may tolerate small amounts of lactose-containing products, others need to avoid all dairy products, choose those with less lactose such as yogurt and some cheeses, take lactase enzyme tablets or opt for non-dairy, plant-based beverages, such as almond or oat milk.
Allergies or intolerances to other foods — for example, soy, gluten, eggs or seafood — may also cause chronic diarrhea.
5. Spicy Foods
Spicy foods like hot peppers get their kick from the chemical compound capsaicin, which appears to trigger diarrhea in some people. "Most people tolerate spicy foods just fine," Dr. Albenberg says. "However, others are sensitive to spicy foods and experience abdominal discomfort, increased gas and bloating, diarrhea and/or rectal burning with the consumption of spicy foods."
Read more: 12 Ways to Beat Belly Bloat for Good
If you take in more caffeine than usual, you may notice an increase in the frequency of your bowel movements. "Caffeine is a stimulant, so it increases the rate that food and fluids move through the intestine and it also causes the cells in the intestine to secrete more fluid," says Dr. Albenberg.
In fact, more than two or three cups of coffee or tea daily can often cause diarrhea, according to the International Foundation for Gastrointestinal Disorders.
When to See a Doctor
Most acute cases of diarrhea will resolve on their own. However, Albenberg advises people with diarrhea "seek medical attention if diarrhea lasts more than two to three days — or sooner if the diarrhea is associated with fever, feeling dizzy or faint, severe abdominal pain or bloody stool or black stool."
If your diarrhea is chronic, you may need further testing to determine if it is caused by an underlying medical condition, like inflammatory bowel disease or celiac disease.
Read more: Food to Eat After Diarrhea
Diarrhea may cause you to lose a lot of fluids. To avoid dehydration, make sure to drink plenty of fluids. That includes water, of course, but also fruit juice and broth, which can help replenish salt and electrolytes, notes the Mayo Clinic. Be aware that apple juice and other high-sugar fruit juices may help with dehydration, but worsen diarrhea, the Mayo Clinic cautions.
Is This an Emergency?
- International Foundation for Gastrointestinal Disorders: "Common Causes of Chronic Diarrhea"
- American College of Gastroenterology: "Diarrheal Diseases – Acute and Chronic"
- National Institute of Diabetes and Digestive and Kidney Diseases: "Symptoms & Causes of Diarrhea"
- Mayo Clinic: "Diarrhea"
- FDA: "Dietary Fiber"
- FDA: "Nutrition Facts Label: Fact Sheet - Sugar Alcohols"