Nutrition

Key points 

  • In general, most patients with IBD should follow the Australian Guide to Healthy Eating. 
  • IBD is a disease that has ups and downs and for this reason there are a few different diets for specific situations. 
  • There is some evidence that suggests that eating less red meat, less sweetened beverages and less fast food is protective against getting ulcerative colitis and possibly keeping you in remission, once your gut has healed.  
  • Diet is a confusing topic with a lot of conflicting information. Talk with an accredited dietitian to find what’s right for you and your IBD. 
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The idea of modifying diet to influence inflammatory bowel disease (IBD) is something that has generated much interest from people with IBD, health care professionals and scientists over the past decade. This has led to dietary research that helps our understanding of the relationship between food and IBD and development of evidence-based dietary recommendations.

In general, most patients with IBD should follow the Australian Guide to Healthy Eating, and do not need to restrict their diet. However, there is emerging or established evidence to support specialty diets for specific situations. Outlined below are the dietary recommendations for:

  1. when IBD is in remission,
  2. when IBD is active, and
  3. to treat complications of IBD.

Determining whether you have active disease or remission is undertaken by endoscopy, imaging and/or blood and stool tests, but can also be indicated by symptoms. It is important to note that symptoms alone are not the best markers of active disease or remission. Many people with IBD will develop a gut sensitivity, meaning symptoms develop without active inflammation.

These are ‘functional’ symptoms, like in irritable bowel syndrome (IBS). On the other hand, active disease can occur without causing many symptoms.

1. Diet when IBD is in remission

There is some preliminary evidence to suggest that dietary factors may assist in keeping remission for longer in people with IBD. Many of these factors are in line with the Australian Guide to Healthy Eating, which describes a well-balanced diet with minimal dietary restrictions beyond those recommended for general health and well-being. Including a good amount of fibre-containing foods is encouraged, unless reducing fibre is necessary due to strictures (narrowing of the bowel) being present (see section 3). Does general dietary guidance differ for Crohn’s disease and ulcerative colitis? The broad dietary recommendations are the same for both Crohn’s disease and ulcerative colitis. There are, however, some early data suggesting that eating more fibre and including fish a few times per week has a protective effect for Crohn’s disease, whilst consuming less red and processed meats may have a protective effect in ulcerative colitis.

2. Diets to treat active IBD

During active disease, the goal of management is to heal the gut (induce remission) and then to keep the gut healed (maintain remission). Your treating doctor will guide you on the status of your disease and appropriate dietary treatments to both induce and maintain remission.

Crohn’s disease

Exclusive Enteral Nutrition (EEN):

EEN is a nutritionally complete medical drink used to induce remission in Crohn’s disease as an alternative to corticosteroids. This therapy involves solely consuming these drinks, usually for six to eight weeks. All food and fluids (except water) are removed from the diet. EEN is a treatment that needs to be commenced and monitored with a gastroenterologist and dietitian to ensure it is done correctly and safely.

Crohn’s Disease Exclusion Diet (CDED):

CDED is a diet that has been developed as an alternative to EEN and shown to be similar for inducing remission in children with mildly active Crohn’s disease. This diet is intended for short term use and involves consuming a medical nutrition drink with an allowance of a limited number of prescribed foods. CDED needs supervision with a gastroenterologist and dietitian to ensure individual nutritional needs are met and the diet is having the intended treatment effect.

Ulcerative colitis

At this stage there is insufficient evidence to recommend a defined dietary strategy beyond healthy eating guidelines for treating active ulcerative colitis.

Complementary and alternative diets that claim to treat active IBD

There are many diets promoted on the internet, social media, and by some complementary and alternative health practitioners, claiming to treat IBD. Some of these diets include Specific Carbohydrate Diet, Paleo autoimmune protocol Diet, plant-based diet, and IBD anti-inflammatory diet. Much of this information is conflicting, and many of these diets are not supported by sufficient scientific evidence to date. Though there may be some “success stories” that you may read or hear about, the experience of some individuals may not be safe or applicable for you. Furthermore, improvement in symptoms may not reflect improvement in inflammation in the bowel. To accurately study the effect of diet on inflammation, studies should assess disease activity using endoscopy, imaging and/or blood and stool tests. The risks with some of these diets is that they could cause more harm and delay remission, lead to unnecessary dietary restriction and nutritional inadequacy. This topic can be confusing, so please discuss this with your IBD team.

Australian Guide to Healthy Eating

australian guide to healthy eating

3. Dietary strategies to treat common complications of IBD

Diet may be used to treat arising problems that commonly occur in people with IBD, as described below. It is recommended that everyone with IBD have an opportunity to meet with a dietitian to discuss and tailor their diet. An IBD specialist dietitian can guide specific dietary education and support for:

Treating malnutrition (under-and over-nutrition)

Both under-and over-nutrition (overweight or obesity) is common in people with IBD and can lead to fatigue, reduced quality of life, depression and may weaken response to medications. People with malnutrition are more likely to become sick and take longer to recover. This can also lead to increased risk of complications after surgery.

Impairment of nutrient absorption is commonly seen in active Crohn’s disease and can lead to specific nutritional deficiencies. Beyond a healthy diet, there is limited evidence for nutritional supplementation in IBD, unless needed to correct specific nutritional deficiencies. Some people may need iron (orally or intravenous), vitamin B12, vitamin D, calcium, folic acid and/or zinc replacement.

If you are concerned that you have malnutrition, it is recommended that you see a dietitian so you can get the right balance of nutrition for your body. Some some supplements can react badly with IBD medication and/or your gut. Make sure you have a talk with your doctor before starting any new supplements.

Iron

Iron is an important mineral that is needed for healthy red blood cells that carry oxygen around your body. Not enough iron can lead to anaemia, a common complication of IBD. People that are anaemic don’t have enough red blood cells. Learn more about other conditions connected to IBD.

Foods high in iron:

  • Beef
  • Spinach
  • Beans like kidney beans and chickpeas
  • Peas
  • Tofu

These foods can be eaten at the same time as vitamin C rich food to increase absorption of iron.

Foods high in vitamin C:

  • Citrus like oranges and grapefruit
  • Cabbage
  • Strawberries
  • Tomatoes

Vitamin B12

Vitamin B12 helps keep the nerve and blood cells healthy. It is absorbed at the end of the small intestine (ileum), so if you have Crohn’s disease or have had surgery in that area you may find it difficult to absorb enough vitamin B12 from just your food.

Foods high in vitamin B12:

  • Clams
  • Beef
  • Tuna
  • Milk
  • Eggs

Vitamin D

Vitamin D, helps your body absorb calcium and can reduce intestinal inflammation. It is a very important vitamin for people with Crohn’s and colitis and there is evidence that suggests IBD is less active in people with healthy levels of vitamin D. Some medications like corticosteroids can interfere with vitamin D absorption.

There is not much vitamin D in food and people usually source it naturally from the sun through the skin.

Calcium

Calcium is important for your bones. People with IBD should make sure they have enough calcium especially if they are using corticosteroids, have osteopenia (low bone density), or osteoporosis (weak bones). Calcium should be taken together with vitamin D.

Foods high in calcium:

  • Cheese
  • Yoghurt
  • Almonds
  • Milk
  • Tofu

Folic acid (folate)

Some medications used to treat IBD, including sulfasalazine and methotrexate, may interfere with the absorption of folic acid. Doctors often recommend that pregnant women, including women with IBD, take folic acid supplements to prevent birth defects.

Foods high in folic acid:

  • Asparagus
  • Eggs
  • Spinach
  • Beef liver
  • Avocado

Zinc

Zinc is important for the immune system, wound healing and many other processes in the body. Absorption of zinc can be reduced by inflammation caused by Crohn’s and colitis and other symptoms like diarrhoea and complications like short bowel syndrome.

Foods high in zinc:

  • Meat
  • Legumes like chickpeas
  • Pumpkin seeds
  • Nuts
  • Dark chocolate

Managing symptoms of irritable bowel syndrome (IBS)

IBS describes symptoms that are from gut sensitivity and/or altered gut movement. This can be managed with dietary and non-dietary therapies such as a low or modified FODMAP diet, changing eating behaviour, or gut-directed hypnotherapy to help control symptoms.

Prevent bowel obstruction

Bowel obstruction (partial or complete) can occur in people with small intestinal Crohn’s disease with a stricture (narrowing of the intestinal space where food and stool passes). If this is suspected or occurs, your gastroenterologist and dietitian can guide you on a modified fibre, low fibre or low residue diet and for how long it would be needed.

Nutritional optimisation before and/or after surgery

Having good nutritional status before undergoing surgery is important to encourage good surgical outcomes, such as a short hospital stay, fast recovery of bowel function and reducing risk of post-surgical complications. Often, medical nutrition drinks are recommended for 7-10 days leading up to planned surgery to optimise nutritional status to improve surgical outcomes. In people with Crohn’s disease, a period of EEN (as described earlier) before planned surgery may also be recommended to both improve nutrition and reduce active disease. This may be used in preference to corticosteroids.

After surgery, your surgeon will gradually allow you to restart oral intake. Some patients may have narrowing at the join of the bowel due to swelling, and require a short-term low fibre diet to allow the site to heal and bowel movements to start. Your surgeon and dietitian will guide the degree and timeframe for fibre restriction, if needed.

Please refer to the Surgery for IBD page for further information.

Diet for people with a stoma

Most people with a stoma have an acceptable output and do not need to modify their diet. Generally, the Australian Guide to Healthy Eating is recommended. One of the roles of the large intestine is to reabsorb water, so ensuring good hydration by having plenty of fluid is important. You may benefit from further consultation with a specialist dietitian if your stoma output is too much, too watery, or too gassy.

Please refer to the Complications with IBD page for further information.

Supplementary therapies -prebiotics and probiotics, curcumin, fish oil

There is little evidence to support the use of most commercial prebiotic (to stimulate growth of beneficial bacteria) or probiotic (live bacteria) supplements for most people with IBD. There may be specific situations where probiotics may be beneficial, including in people with an ileoanal pouch and recurrent pouchitis.

Small studies suggest that curcumin may be helpful in people with ulcerative colitis but further studies are needed. Fish oil supplements are not likely to be beneficial for IBD but can be good for general health.

Please refer to the Complementary and Alternative Therapies in IBD page for further information.

Useful sources of general dietary information

Acknowledgements:

This resource was developed in 2021 by the GESA IBD Patient Information Materials Working Group.

The Crohn’s disease and ulcerative colitis videos were developed by The Queen Elizabeth Hospital, Basil Hetzel Research Institute and University of South Australia.