A single serving of a specific food is unlikely to cause constipation in most people. However, eating a lot of low fiber foods, eggs, onions, or legumes may cause problems for some.

Constipation can also occur due to dehydration, stress, a disrupted daily routine, and underlying health conditions, such as irritable bowel syndrome (IBS).

This article will look at which foods can cause or worsen constipation and some other potential causes.

A woman in a grocery store looking at a product label to see if it contains foods that cause constipation.Share on Pinterest
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In most healthy people, a single, specific food will not directly cause constipation. However, people with persistent digestive symptoms, such as chronic constipation, may find certain foods make it worse.

Occasional constipation is common, and most people will experience it at some point in life. Some potential causes include:

There are also many digestive conditions that can cause constipation, such as:

The following sections will discuss some foods that may cause or worsen constipation in some people.

It is important to note that these foods are not an issue for most people. Do not make major dietary changes, such as cutting out a whole food group, without consulting a doctor or dietitian.

Refined grains

Foods that contain refined flours, such as white bread, pizza dough, cakes, and baked goods, are all low in fiber. When part of a low fiber diet, this may contribute to constipation.

However, these specific foods are not the cause of the constipation. Instead, the cause is an imbalance between different food groups. Eating more fruits, vegetables, and wholegrains may help.

It is worth noting that some people with digestive conditions find that eating high fiber foods can make their symptoms worse. If increasing fiber does not help, it may be worth talking with a doctor.

Salty snacks

Foods that are very high in salt may contribute to constipation by worsening dehydration. When people eat a lot of salt but do not get enough fluids, the body pulls moisture from cells instead, and from the colon. This causes the stool to become dry and difficult to pass.

Salty foods that could contribute to this effect include:

  • chips
  • fries
  • processed meats
  • freezer dinners

Garlic and onions

Some people with IBS have difficulty absorbing carbohydrates known as fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs).

According to Monash University, eating foods high in FODMAPs can cause constipation for this group. They created the low FODMAP diet to help people who experience this.

Some of the most common high FODMAP foods are garlic and onions. They are present in many dishes from cuisines around the world, but for those who have difficulty digesting FODMAPs, they can trigger symptoms.

Learn more about the low FODMAP diet here.

Legumes

Similarly, legumes can be high FODMAP and difficult to digest for some people. Legumes include foods such as:

  • beans
  • chickpeas
  • lentils

Whole wheat, barley, or rye

While a low fiber diet can contribute to constipation in some people, others find that too many high fiber, high FODMAP foods, such as whole wheat, barley, and rye, can trigger constipation.

Bananas

Bananas are part of the banana, rice, apple sauce, toast (BRAT) diet, which doctors previously recommended to treat diarrhea. This was due to these foods’ ability to slow down bowel movements. As a result, these foods may not be a good option for people who have constipation.

According to Monash University, ripe bananas are also high FODMAP, which may mean that some people with IBS have to avoid them. Unripe bananas are low FODMAP and may be easier for those with IBS to tolerate.

Eggs and other allergens

Some people believe that eggs can cause constipation. However, there is not much scientific evidence that supports this. They are a low fiber food, though, so eating a lot of them within a low fiber diet may contribute to constipation.

Egg allergies are also among the most common food allergies, which could explain why some people have difficulty digesting them. In some people, chronic constipation may signal a food allergy.

A 2023 study on constipation in 305 children found 15% had a food allergy, and that eggs were one of the main triggers.

If a person’s body does not respond to taking laxatives or making other dietary changes, the person may wish to ask a doctor if allergy testing could be appropriate for them.

Milk and dairy products

Some people report that milk or cow dairy contributes to constipation. This could occur for several reasons.

Firstly, some dairy products, such as milk and soft cheeses, are high FODMAP. Another potential explanation is an allergy to dairy proteins, such as whey or casein.

Those with lactose intolerance typically experience diarrhea when they consume dairy, but a 2022 study notes that constipation also occurs in around 30% of cases.

For many people, eating more high fiber foods can ease constipation. High fiber foods include:

  • most vegetables, including carrots, peas, broccoli, and okra
  • fruits, including kiwis, berries, avocados, and oranges
  • wholewheat bread, pasta, and brown rice

When increasing fiber intake, it is also important to drink enough fluids to prevent dehydration. Also, it is best to increase fiber intake slowly to prevent a constipating effect.

The Institute of Medicine recommend consuming 19–38 grams of fiber per day, depending on age, sex, and stage of life. Pregnant people and older adults may need more fiber than others to prevent constipation.

Some specific foods that may help with constipation include:

  • Kiwi fruit: According to a 2023 trial, eating 2 green kiwi fruits per day can increase bowel movements among people with functional constipation or IBS.
  • Prunes: A 2018 study found that eating prunes increase bowel movement frequency among adults with low fiber diets and infrequent bowel movements. However, they are high FODMAP, which may make them unsuitable for some people with IBS.
  • Fruit juices: Unsweetened fruit juice may be helpful for young children, whose digestive systems are not yet matured. Apple, pear, or prune juices can be a source of fiber and help increase fluid intake.

If eating more fiber does not help or makes constipation worse, speak with a doctor.

Other aspects of a person’s lifestyle — such as their exercise routine, bathroom habits, and mental health — can also influence digestion.

To prevent or relieve constipation, they may wish to try:

  • using the bathroom as soon as the need strikes
  • regular moderate exercise
  • minimizing the use of laxatives and enemas, unless directed by a doctor
  • seeking help with managing chronic health conditions, such as diabetes
  • seeking support for mental health conditions, such as anxiety
  • learning stress management techniques, such as breathing exercises
  • speaking with a doctor about any medications that could be causing constipation

Constipation is common, and most people experience it occasionally — particularly if their usual routine or diet has recently changed.

However, chronic constipation means that the digestive system is not functioning as it should. People with frequent or reoccurring constipation may have a health condition.

People should speak with a doctor if they experience any of the following symptoms:

  • severe constipation that does not respond to over-the-counter laxatives or dietary changes
  • constipation that keeps coming back
  • abdominal pain
  • blood in the stool
  • constipation alongside additional symptoms, such as vomiting

What causes constipation can vary from person to person. For some, eating a diet low in fiber can cause or worsen constipation. In this case, eating more fruits and vegetables and staying hydrated may help.

For others, food allergies, intolerances, or FODMAPs can cause or worsen constipation. Finding the cause of constipation can help these people determine which foods they should avoid.