What is the best diet for Crohn's disease?

What to eat during a Crohn's flare-up

Crohn's disease is a form of inflammatory bowel disease (IBD) in which one or more parts of your gut become inflamed. There isn't clear evidence that food can cause this chronic condition, but certain foods can trigger symptoms to flare up - which could involve bloating, abdominal pain, and diarrhoea.

What you eat during and in-between flare-ups is important not just for managing your symptoms, but for your overall health. You need to provide your body with the essential nutrients it needs, and for this you need to focus on healthy foods that are easy for your gut to digest.

A Crohn's disease diet that excludes symptom-triggering foods is sometimes called a Crohn's disease exclusion diet, or CDED. A 2022 study found that following a CDED can be an effective way to bring about remission in both adults and children¹. Remission describes the periods of time when you are free from the troubling and uncomfortable symptoms of this condition.

You should ask your healthcare expert for advice before undertaking any kind of Crohn's disease diet. People with this condition can have different food triggers and needs, and experts can help make sure that whatever foods you exclude are replaced with ones that contain all the vitamins and minerals you need for a balanced diet.

It may be that you're unsure what your triggers are. For this, a healthcare expert can put you on an elimination diet, in which you cut out certain foods one by one and note down if or when your symptoms change².

Naomi Leppitt, gut dietitian at Dietitian Fit & Co, talks through the most common foods that can make Crohn's disease flare-ups worse, and what you can eat instead.

Swap to low-fibre foods

"The main thing to avoid during a Crohn's flare-up is fibre," says Leppitt. "When your gut is inflamed, you want to make it as easy as possible for it to digest and absorb food and fluids. Fibre is the indigestible element of plant-based foods - it's found in the skin, seeds, and stalks of fruits and vegetables, as well as whole grains, nuts, and seeds."

Leppitt adds that fibre usually has great health benefits. For example, it can help keep your bowel habits stay regular and formed, and can even improve your blood pressure, blood cholesterol, and blood sugars. However, while your Crohn's disease symptoms flare up, it's best to stick to lower-fibre options.

Choose plain foods

"You should also stay away from anything too spicy, sugary, or fatty and opt for plainer foods instead," says Leppitt. It's thought that the chemicals in spicy foods can aggravate your gut. It can also be irritated by the fat in highly processed fatty and sugary foods, because this fat can't be absorbed fully by your small intestine.

Leppit recommends a casserole with peppers accompanied by mash or a cod and prawn stew, with peeled, deseeded courgette and boiled rice on the side.

Avoid alcohol, caffeine, and lactose drinks

Leppitt points out that people with Crohn's disease should also watch what they drink during flare-ups. Alcohol, caffeine, and milk can be particularly triggering.

Alcohol can irritate the lining of your gut and can even cause malabsorption and bleeding. According to the Crohn's and Colitis Foundation, this is why you should always ask your doctor whether drinking alcohol is safe while you are taking IBD medications³. Caffeine acts as a stimulant for bowel movements, which makes diarrhoea worse. The lactose in milk - and other dairy products - is a sugar that can also be difficult for your gut to digest during a flare- up.

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Should you try a liquid diet?

For some people, a Crohn's disease diet may mean temporarily avoiding solid foods altogether. Instead, they consume a formulated liquid made up of essential nutrients including proteins, carbohydrates, and vitamins. However, this may only be recommended if your doctor has advised this and⁴:

• Your symptoms are severe.

• You're having difficulty absorbing nutrients.

• You've had intestinal surgery.

• You have short bowel syndrome.

You should only ever follow a liquid diet under the guidance and supervision of a healthcare expert. If you're really struggling with your symptoms, despite avoiding common trigger foods, Leppitt recommends speaking to your dietitian, IBD nurse, or doctor for more guidance on whether a liquid diet could be right for you, and for getting specific supplements.

What to eat during remission

You should also be mindful of what you eat during the times when your symptoms aren't causing you bother. Leppitt explains:

"The levels in your body of various vitamins and minerals - including zinc, iron, calcium, and vitamins K and B12 - are at risk of being low due to Crohn's disease diarrhoea, poor absorption of nutrients, or the need to avoid certain foods during flare-ups.

"When symptoms are improved and Crohn's is in remission, it's important to reintroduce foods packed with these nutrients."

It's also important to stay as hydrated as possible with water and rehydration solutions, alongside a Crohn's disease diet.

Further reading

1. Yanai et al: The Crohn's disease exclusion diet for induction and maintenance of remission in adults with mild-to-moderate Crohn's disease (CDED-AD): an open-label, pilot, randomised trial.

2. Nutritional therapy for IBD: Crohn's Disease Exclusion Diet (CDED).

3. Crohn's and Colitis Foundation: Substance abuse.

4. IBD Relief: Liquid diets and inflammatory bowel disease (IBD).