Some foods, such as spicy and fatty foods, could worsen the symptoms of irritable bowel syndrome (IBS) with diarrhea (IBS-D). Other foods, such as those low in FODMAPs, could help people manage the condition.

IBS is a common gastrointestinal condition that causes abdominal pain or discomfort. IBS can also cause changes in a person’s bowel habits. When these changes often involve diarrhea, doctors may diagnose IBS-D.

This article examines the effect of diet on IBS-D. It discusses the importance of keeping a food journal, the role of fiber, and low FODMAP diets. It also discusses foods that may trigger or ease IBS-D symptoms.

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It may be helpful for an individual with IBS-D symptoms to keep a food journal. They can record the foods they eat and any worsening or improvement in IBS-D symptoms. A food journal can help someone understand how their body responds to different foods, which foods to avoid, and which they can eat safely.

There is a lack of research into whether keeping a food journal can help people manage their IBS. One potential issue is that finding accurate correlations between foods and IBS symptoms may be difficult.

A 2019 study suggests that keeping a Food and Symptom Times (FAST) diary allows people to correlate some foods with IBS symptoms. However, the study authors note that the reliability of this method remains uncertain.

Explore 10 signs and symptoms of IBS.

According to a 2019 review, a high fiber diet may help with some types of IBS. In particular, there is evidence that eating higher-fiber foods can improve the symptoms of IBS-C. This form of IBS often involves constipation.

There is little scientific research on fiber intake and IBS-D. Scientists do not yet know whether fiber can help with IBS-D or worsen the condition.

The Dietary Guidelines for Americans 2020–2025 recommends an adult consume 22–34 grams (g) of fiber daily.

It is best for people to gradually add fiber to the diet, starting with 2–3 g per day. Suddenly increasing fiber intake can create gas and trigger IBS symptoms.

Learn about dietary fiber.

A 2019 review suggests that low FODMAP diets can help with IBS, at least in the short term. A low FODMAP diet involves limiting certain foods containing:

  • F: fermentable
  • O: oligosaccharides
  • D: disaccharides
  • M: monosaccharides
  • A: and
  • P: polyols

There is some evidence that low FODMAP diets may help with IBS-D specifically. A 2017 review states that these diets may reduce how often a person passes stool in people with IBS-D.

However, a 2020 review notes the low quality of many studies on IBS and low FODMAP diets. Although several papers suggest that such diets can help with IBS-D, more research is necessary.

Learn more about low FODMAP diets.

People with IBS can try adding high fiber foods to their diet. The table below shows some foods to try.

Food Examples
Whole grain cerealsporridge oats, quinoa flakes, brown rice, rice bran, sourdough spelt bread, and gluten-free multigrain bread
Vegetablescarrots, green beans, sweet potatoes, corn, cabbage, cassava, and eggplant
Legumeslentils, chickpeas, broad beans, peas, and soybeans
Fruitsberries, rhubarb, kiwi, mandarin, passion fruit, coconut, guava, and oranges

To date, there is no reliable scientific evidence that certain foods are beneficial for IBS-D.

Recipes to try for IBS.

There is some evidence that diets high in certain nutrients may worsen symptoms of IBS. The table below shows foods that may trigger IBS symptoms.

Food componentsExamples
Glutenwheat, rye, barley, and malt
Fathigh fat foods such as pizza, fries, fatty meats, and ice cream
Othercaffeine, alcohol, and spicy foods

High FODMAP foods to avoid

The table below shows FODMAP-containing foods that people with IBS may wish to avoid.

Food componentExamples
Oligosaccharides cabbage, onions, garlic, wheat, rye, beans, and watermelon
Lactose milk, ice cream, yogurt, and soft cheeses
Fructoseapples, mangoes, watermelon, honey, and fruit juice
Polyolsavocado, cherries, pears, cauliflower, mushrooms, and sweeteners ending in “ol”

The evidence around foods to avoid with IBS is limited. While there are some studies, these may not be of great quality. Additionally, the studies do not always focus on IBS-D. Scientists still have much to learn about which foods to avoid for IBS-D.

The way people respond to foods varies widely. Taking a food-journaling approach is likely the best way people can identify the foods that are helpful and harmful to them.

Learn more about foods to avoid with IBS.

Nondietary tips may help some individuals manage IBS-D symptoms. A 2020 review discusses some possible interventions for IBS. These include the following nondietary interventions:

Taking IBS-D medications, including antidiarrhea drugs, can also improve its symptoms.

Complementary therapies for IBS.

IBS-D causes gastrointestinal discomfort, as well as diarrhea. Although some evidence suggests that some foods can worsen this condition, the evidence for this is mixed.

Research does suggest that a low FODMAP diet can lessen symptoms of IBS-D. However, much research on IBS and low FODMAP diets is low quality.

Many studies on diet and IBS do not investigate IBS-D specifically. For instance, some evidence suggests that high fiber diets could help with IBS-C. Scientists do not know whether the same is true of IBS-D.

Keeping a food diary may help individuals with IBS-D to determine the foods that worsen or improve their symptoms.