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Crohn’s disease and dietary fibre: what’s the connection?

Along with other treatment methods, diet is an important part of managing Crohn’s disease. Some people with Crohn’s disease may benefit from reducing their dietary fiber intake. This type of food is difficult to digest and can make symptoms worse, especially during a flare-up.

Although dietary factors cannot cure or cause Crohn’s disease, they can affect its symptoms, especially during a flare-up.

Doctors recommend that people with inflammatory bowel disease (IBD) follow a diet with reduced fiber intake. However, it is important to consider that certain types of fiber may be beneficial for people with IBD.

This article explores the different types of dietary fiber and their effects on Crohn’s disease. It also explains what foods to eat and avoid, and what supplements to consider taking.

Crohn’s disease is a form of IBD. It is a long-term condition that causes irritation and inflammation in the digestive tract.

The disease usually affects the beginning of the large intestine and the lower part of the small intestine (ileum). However, it can affect any part of the digestive tract, from the mouth to the anus.

On 3 million adults in the United States had the disease in 2015, a figure that has increased significantly over the past two decades.

The exact cause of Crohn’s disease is unknown, but experts believe the condition results from an abnormal immune response.

Diet and nutrition play an important role in controlling IBD symptoms, but there is no single diet that works for everyone.

There is no evidence to suggest that any particular food or diet can cause, prevent, or cure Crohn’s disease. However, many doctors recommend a low fiber or “low residue” diet.

Fiber is a substance that remains undigested as it passes through the small intestine. It is present mainly in plant foods, such as fruits, nuts, grains and vegetables.

Different types of dietary fiber affect digestion in different ways. There are two main types of dietary fiber: soluble and insoluble.

Learn more about soluble and insoluble fiber.

Soluble fiber

These fibers dissolve in water, which helps absorb water in the intestine. This slows the transit time of food through the intestine. Soluble fiber takes on a gel-like consistency during digestion, which helps reduce diarrhea and delay bowel emptying, especially during flare-ups.

Insoluble fiber

These types of fibers do not dissolve in water but bundle it together in the intestine. As a result, they move faster through the intestine and are more difficult for the body to digest. They can make symptoms worse and cause diarrhea, pain, and bloating. Insoluble fiber can also block the intestinal tract if there is severe inflammation or narrowing of the intestines, called strictures, during flare-ups.

Learn more about Crohn’s disease and strictures.

Many studies actually report that avoiding fiber may not be beneficial for people with Crohn’s disease.

A 2015 study found that people with Crohn’s disease who didn’t avoid fiber-rich foods were about 40% less likely to have a flare-up than those who avoided them.

Another one 2015 study found that a plant-based diet was effective in reducing gut inflammation and supporting overall health in people with IBD.

However, the study authors mention that a low-residue diet without insoluble fiber could accelerate an imbalance of microorganisms in the gut, called dysbiosis. They conclude that large amounts of dietary fiber are not harmful for people with IBD, but seem rather beneficial.

Other research has also explored the benefits of fiber consumption and the lower likelihood of developing Crohn’s disease. A study 2017 found that a high-fiber diet can reduce the risk of developing the disease.

Below are some examples of high fiber foods in different food type categories:

Cereals and seeds




Foods to Avoid

Most foods contain both types of dietary fiber. Conventionally, doctors advise people with symptoms such as bloating and diarrhea to avoid insoluble fiber.

Some of the foods they generally ask people to avoid include:

  • vegetables and fruits with skin and seeds, such as apples
  • raw green vegetables, especially cruciferous ones, such as cauliflower
  • whole grains
  • whole nuts
  • high-fat foods, such as butter
  • alcohol and caffeinated beverages
  • lactose, which is found in milk and soft cheeses
  • sweet foods
  • spicy foods
  • non-absorbable sugars, such as mannitol, found in some types of fruit and juice, including pear and peach
  • fatty or fried foods

Many people with IBD may need to take supplements to compensate for the deficiency resulting from active bowel inflammation, food avoidance, and malabsorption.

Malabsorption makes it difficult for the small intestine to absorb needed nutrients, such as proteins, fats, sugars, vitamins, and minerals. It can occur as a result of inflammation of the intestines.

A person should speak with a doctor before purchasing vitamins, supplements, and herbal formulas. If the pills are causing digestive symptoms, they may consider taking supplements in liquid or powder form.

It’s also crucial to check the label for artificial colors, sugar alcohols, lactose, and preservatives. Some people may be sensitive to even small amounts of these substances.

Here are some supplements people with IBD might need:

A study 2019 reviewed omega-3 fatty acids. It has shown that these reduce inflammation, decrease disease activity and increase the quality of life in people with Crohn’s disease.

However, a 2019 review concluded that there was not enough evidence to confirm that probiotics were effective in treating IBD and maintaining gut microbiota balance.

The same foods do not trigger symptoms in all people with Crohn’s disease. A person may wish to explore which foods are safe for them and which trigger symptoms.

Keeping a food diary or diary and tracking their symptoms can help people figure out which foods are causing problems.

This information can be helpful when a person wants to discuss their treatment options with a doctor or dietician.

Learn more about IBD and ways to manage them by visiting our hub.

According to some research, it is common for people with Crohn’s disease to limit their fiber intake due to the insoluble nature of many fiber-rich foods. However, in some people, foods high in fiber may reduce the risk of flare-ups. They may even reduce the risk of developing IBD in the first place.

It is important to note that all dietary factors can affect people with Crohn’s disease differently. Keeping a food diary to track food intake and symptoms can help a person determine which dietary factors are making their condition worse.