Nutrition and inflammatory bowel disease

Nutrition and inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes both ulcerative colitis and Crohn’s disease, affects the digestive system and can prevent you getting proper nourishment from your food. Additionally, some foods may make your symptoms worse.1,2

To keep well, you may need to make some changes to your diet, including avoiding certain foods which can cause irritation and make your symptoms worse and eating more of certain foods to ensure you get the right nutrition. Read on to find out what foods these ‘trigger’ foods are.

Why might I not be getting enough nutrition from my food?

A man eating a healthy breakfast.

Even if you are eating a healthy, balanced diet, you might find that you are not getting what you need from your food, because your gut is damaged, or because you have diarrhoea which decreases the nutrients your gut can absorb.1,2

You might also find you have to alter or reduce the amount you eat if:

  • you have pain and discomfort caused by your condition
  • certain foods trigger a flare or make your symptoms worse
  • you are doing therapeutic fasting, which involves not eating solid foods, to allow the gut to heal.

Are there foods I should avoid?

To understand why food has an impact on your gut, it is important to understand the community of micro-organisms that live in your gut, called the microbiota. The microbiota is a rich ecosystem that performs a variety of functions in our bodies and plays a vital role in your health. The bacteria breakdown the foods that the body cannot digest, produce important nutrients, regulate the immune system and protect against harmful germs. A healthy microbiome contains a variety of bacterial species and a change in this community of bacteria can cause inflammation.3

Some people with IBD find that specific foods can cause their symptoms to worsen, such as high fibre foods, dairy or alcohol, but this does not mean you should eliminate those from your diet as restricting the range of foods you eat has serious implications and could make you unwell.1 Adults need to eat 2000-2500 calories per day, though this can vary depending on age and activity, and how quickly your body uses energy. If you absorb fewer calories than needed, you will lose weight, and more than needed will lead to weight gain.4

Foods which you may want to avoid in a flare include4

  • Insoluble fibre foods that are hard to digest such as fruits with skin on, seeds, raw green vegetables (especially vegetables like cauliflower and broccoli), whole nuts and whole grains
  • Lactose, a type of sugar found in dairy
  • Sugary foods
  • High-fat foods like fried or greasy food, butter, cream, and margarine
  • Alcohol and caffeinated drinks like beer, wine, fizzy drinks, and coffee
  • Spicy foods

It is important that you consult your IBD team before eliminating any foods.

My food diary

My food diary

What are examples of foods I should include in my diet?

No diet has been proven to help people with IBD. Everyone is different so what works for one person may not work for another. You may want to consider focussing on the following:

What does a balanced diet look like?

Generally, to have a healthy and balanced diet, people should aim to eat a wide range of food from all food groups:5

  • At least 5 portions of fruit and vegetables every day
  • Meals based on high-fibre starchy foods (potatoes, bread, and rice)
  • Some dairy products (or alternatives)
  • Protein such as poultry, red meat, eggs, as well as beans and legumes
  • Oils or fats in small amount
Infographic showing the balanced portions of each food group. 40% fruits & vegetables, 25% carbohydrates, 25% protein, 10% fats.

Can getting insufficient nutrients in my diet make my symptoms worse?

There are some symptoms of IBD which worsen because of a poor diet or eating foods which irritate your gut, as discussed above. Some foods may contribute to your symptoms, and it is useful to try to identify those and eliminate them from your diet. One way of doing this would be to keep a food diary and record what you are eating and what symptoms you have, if any.

Lots of people with IBD experience extreme tiredness called fatigue. This is sometimes caused by anaemia which in turn is caused by poor absorption of nutrients in the gut, or lack of the right nutrients in your diet.1

Getting the right nutrition and avoiding triggers

Even though specific diets have been shown to bring about positive outcomes, there is currently no scientific consensus regarding an appropriate diet that would benefit all IBD patients.5

It may take some time to work out what range of foods is best for you. Keeping a food diary is a good first step if you have been diagnosed with IBD, and you may already have been asked to start one by your doctor. An NHS dietician can give you tips and advice, such as how to avoid dehydration, constipation or bloating.1,2,6

Read about specialist roles in your care team, including IBD nurses and dieticians in the Navigating the NHS section.

You can find out more about inflammatory bowel disease from these independent organisations

Crohn’s and Colitis UK

Crohn’s & Colitis UK has some extra information about diet and IBD.

Alcohol and IBD

Some people with IBD find alcohol can worsen their IBD symptoms as it may irritate their gut or cause dehydration.


IBD = Inflammatory bowel disease.

  1. Lucendo AJ, De Rezende LC. Importance of nutrition in inflammatory bowel disease. World J Gastroenterol 2009;15(17):2081–088.
  2. Reddavide R, et al. The role of diet in the prevention and treatment of Inflammatory Bowel Diseases. Acta Biomed. 2018 Dec 17;89(9-S):60–75.
  3. Crohn’s & Colitis Foundation. What Should I Eat? Accessed October 2023.
  4. de Castro MM, et al. Role of diet and nutrition in inflammatory bowel disease. World J Exp Med. 2021;11(1):1–16.
  5. The Association of UK Dieticians. Management of Crohn’s disease - recent developments. developments.html. Accessed October 2023.