Even roughage-rich foods lead to bathroom struggles in some cases. You might be surprised to learn which foods can cause irregularity woes.
6 “Healthy” Foods That Can Keep You from Pooping, Say Clinical Experts
Published on Jul. 01, 2025
Why healthy foods can disrupt digestion
“The biggest misunderstanding people have is assuming that nutrient-dense foods are always gut-friendly,” says Alyssa Simpson RDN, CGN, CLT, a digestive health dietitian. “Some of the healthiest foods can be hard to digest if your gut is inflamed or imbalanced.”
“The digestive system consists of an estimated 40 trillion good bacteria,” adds Amy Bragagnini MS,RD,CSO, a registered dietitian with the Academy of Nutrition and Dietetics. These microbes help your gut effectively break down food, allowing your body to digest and absorb nutrients necessary for metabolism.
So, if your gut isn’t healthy, digestive problems may result. Gastrointestinal (GI) response can also vary based on your hydration status, medication usage, overall diet, food sensitivities or intolerances, and other factors, too.
Key contributing factors that can vary up your bowel regularity can be:
- Fiber: Per the Mayo Clinic, soluble fiber (like in oats) dissolves in water, slowing down digestion and helping to regulate bowel movements; insoluble fiber (like in whole wheat) generally adds bulk to stool, speeding up digestion and helping to prevent constipation. Fiber may help with regularity when people are hydrated and have a healthy gut, or worsen bloating, discomfort, and constipation for those with GI issues.
- Sugar alcohols: They’re a type of carb found in low-calorie sweeteners, like xylitol and sorbitol, and occur naturally in some veggies and fruits, according to the Cleveland Clinic. They feed beneficial gut bacteria, but they can contribute to bloating, gas, and diarrhea since they pull water into the intestines and aren’t fully absorbed, explains Harvard University’s medical school.
- “Trigger” foods: Food sensitivities are immune (not allergic) reactions to foods that can result in chronic gut symptoms, like irregular bowel function, bloating, and cramping. Identifying and removing “trigger” (problematic) foods may improve gut and overall health.
It can take time to figure out what foods are best for your individual gut health, says Bragagnini. Consuming a varied diet, including a mix of fermented foods, fruits, vegetables, beans, and whole grains, can help optimize gut health from the get-go.
While individual food “triggers” may affect your poop, also consider the context of the entire diet. But know that these six nourishing foods (or food categories) might mess with your digestion. In many cases, you can gradually add these foods into your diet since you’ll want to include most in your nutrient-rich eating plan.
Stay hydrated, too.
Healthy foods that can cause digestive issues
1. Protein bars
“Even the ‘clean’ bars can have sugar alcohols or added fibers that are rough on digestion,” says Simpson.
For instance, protein bars may contain chicory root fiber. Per Phytochemistry Reviews, chicory root fiber contains inulin. Inulin ferments in the large intestine, which may lead to more bowel movements, softer stools, or, in large quantity, possibly diarrhea. Sugar alcohols may contribute to diarrhea, too.
However, not all protein bars include these ingredients, and whole-food bars are generally gut friendly.
2. Bran-heavy cereals
They’re a nutritious way to start the day right, but fiber-rich, wheat bran-heavy cereals are high in insoluble fiber. Too much insoluble fiber at once may make it harder for stool to pass and worsen digestive symptoms, especially if you’re not adequately hydrated.
According to 2025 research published in the peer-reviewed journal Foods, wheat bran fiber can be useful for relieving constipation and supporting intestinal health.
3. Dairy foods
If you have lactose intolerance, bloating and diarrhea can occur due to malabsorption of lactose, a naturally occurring sugar in dairy products. In the U.S., around one in three people experience lactose malabsorption, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
“Some people struggle digesting foods containing milk because they have too little of a specific enzyme called lactase, which breaks down the sugar in milk,” says Bragagnini.
Note that a food intolerance is not an allergy, per Gastroenterology & Hepatology.
4. Dried fruits
“Dried fruit is sneaky—just a few pieces may pack a ton of fiber and sorbitol, which can be too much for sensitive guts,” says Simpson. This is especially true of prunes and dried apricots, both concentrated sources of sorbitol. According to a case study in Canadian Family Physician, if you overdo sorbitol, that may trigger diarrhea due to its laxative properties.
However, in general, moderate dried fruit consumption can promote regularity.
5. Onions and Garlic
“Although healthy and delicious, onions and garlic can be surprisingly irritating when your gut is out of balance,” says Simpson.
Garlic and onions contain fructans, which are FODMAP carbs, that aren’t easily absorbed in the small intestine, says the the Academy of Nutrition and Dietetics. So, they ferment in the colon, producing gas and drawing water into the intestines. Fermentation can cause GI symptoms, including bloating, abdominal pain, and possibly diarrhea, especially for people with fructan sensitivity, says an article in Current Gastroenterology Reports, or irritable bowel syndrome (IBS).
Still, these aromatics can support a healthy gut microbiome.
6. BRAT foods
A BRAT diet (bananas, white rice, applesauce, and toast) used to be a regular part of diarrheal treatment. However, the Cleveland Clinic says it’s not always the best advice. Combined, these foods may help firm up stools, but they could be problematic if eaten regularly without experiencing diarrhea.
Applesauce contains pectin, a soluble fiber that may help firm up loose stool. Unripe bananas contain resistant starch, says Johns Hopkins, and white rice and white toast both typically lack fiber, which may slow digestion and make your stool harder and difficult to pass.
What to do if you’re experiencing digestive upset
- Track symptoms. Record what, how much, and when you’re eating, plus subsequent digestive issues.
- Boost liquid when boosting fiber. Adequate water consumption can help prevent constipation.
- Beware of overly “clean” eating. Don’t try to “fix” symptoms by eating even more roughage. Calm the gut first.
- Do a reset. Consider a one- or two-week pause of what you suspect could be a problematic food before slowly reintroducing one ingredient at a time.
- See a dietitian or doctor. They’ll help identify food intolerances or sensitivities, slowly remove foods that disagree with your digestive system, and add nutritionally-balanced foods that you can digest, says Bragagnini.
When to see a doctor
Visit your doctor if you’re experiencing:
- Prolonged or frequent bouts of watery diarrhea or chronic constipation
- Blood in your stool
- Unintentional weight loss
- Severe cramping or increased abdominal pain
- Persistent symptoms without improvement
Your doctor can help with GI symptom management and treatment. A registered dietitian (RD or RDN) can recommend individualized diet modifications.
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