Diet Issues in Inflammatory Bowel Disease

Amanda Proctor
Accredited Practising Dietitian
Monash Medical Centre, Melbourne

What is Inflammatory Bowel Disease (IBD)?

IBD is a term used to describe two main diseases, Crohn's disease and Ulcerative Colitis. These are chronic inflammatory conditions affecting the gastrointestinal tract. See Ulcerative Colitis and Crohns' disease for more information.

Did my diet cause IBD?

The cause of IBD is unknown and to date there is no evidence that dietary factors cause IBD.

Is there a special diet for IBD?

No, there is no special diet for IBD. A healthy, balanced eating pattern is recommended which is especially important for normal growth and development in children. However, a small number of people with IBD may need modification to their eating pattern, particularly if the flare-up is prolonged or surgery is required.

  • Adjusting your diet may help to:
  • Alleviate symptoms of IBD
  • Correct nutritional deficiencies
  • Maintain body weight
  • Promote growth and development in children

How do I manage IBD?

  • Understand your disease. Talk to your gastroenterologist and join the Australian Crohn's & Colitis Association (look up your local branch under Patient Services).
  • Follow a healthy balanced eating plan. If you would like to know more about healthy eating, see 'What Is A Healthy Diet?'.
  • Modify your eating pattern, if necessary, during flare-ups.
  • Take your medications as prescribed by your gastroenterologist.

Are nutritional supplements necessary?

Some people go through flare-ups of their disease with little or no change in appetite whilst others struggle to eat enough. These are the times when you may need to modify your eating. Nutritional requirements increase with infection, inflammation and fever. The best guide to whether you are eating well is whether you can maintain your bodyweight. You may need extra protein and calories when weight loss and poor appetite persist. Liquid supplements are available which provide additional nutrients to supplement food intake.

If you are too unwell to eat enough, liquid supplements may be given via a tube through the nose into the stomach or small bowel. This type of feeding (enteral nutrition) is commenced in hospital. If the disease is severe and the food is not being absorbed by your bowel, nutrition can be given via the vein (parenteral nutrition). This is rarely required and always commenced in hospital.

What about Vitamin and Mineral supplements?

Most people generally do not require vitamin and mineral supplements and your dietitian or gastroenterologist can advise you.

You may need supplementation -

  • during long periods of flare-ups with poor food intake
  • If blood tests show that you have low levels of folate, vitamin B12 or iron
  • During with prolonged steroid therapy (especially calcium, 1000 mg/day)
  • With disease/resection of the terminal ileum (vitamin B12 injections every 3 months)
  • With excessive diarrhoea (zinc, potassium, magnesium and copper)
  • With long term sulphasalazine therapy (folate)

Sometimes a low residue (low fibre) diet is necessary

A low fibre diet during a flare-up may be helpful in controlling diarrhoea. It may also mimimise symptoms of pain and nausea in people with strictures (narrowing of the bowel). If a low fibre diet is required during flare up, it is best to avoid seeds, nuts, legumes, dried fruits, skin of fruit, corn, wholegrain/wholemeal breads and cereals.

The importance of adequate fluid intake

It is important to take adequate fluid (at least 6-8 cups/day). Extra fluid may be required with the fluid loss of diarrhoea.

Lactose (milk sugar) intolerance

Lactose is a natural milk sugar which is digested by the enzyme lactase, found in the lining of the small bowel. Lactase levels may fall during flare-ups in some patients with extensive small bowel Crohn's disease, resulting in lactose entering the large bowel. This can cause cramping, gas, diarrhoea and abdominal pain. Some other IBD patients appear to be sensitive to milk yet they do not have lactase deficiency. It may be necessary for these patients to avoid lactose temporarily during flare-ups, but most people with IBD are able to tolerate milk and in fact it is beneficial for them.

If you do need a low lactose diet, please refer to the Lactose free diet.

Do I need a low fat diet?

Fat is an important source of energy particularly if you are prone to weight loss. It is also necessary for growth and development in children. However, some people with Crohn's disease may need to decrease fat intake if suffering from fatty diarrhoea (steatorrhoea). Your gastroenterologist will be able to diagnose this.

If you need to reduce your fat intake, limit

  • Fatty foods - chips, chocolate, pastries, fried foods, biscuits, cakes
  • Added fats - butter, margarine, oil, lard, mayonnaise, cream, dressings, dripping

Choose instead

  • Low fat dairy products
  • Lean cuts of meat

If steatorrhoea is severe, your dietitian can advise on MCT (medium chain triglyceride) supplementation. Lipase (enzyme to digest fat) and bile salts are required for normal fat absorption. MCT's are readily absorbed without lipase and bile salts. Supplementing the diet with MCT's improves fat absorption in people with steatorrhoea.

Are there foods I need to exclude from my diet?

There is no evidence to suggest that particular foods play a role in IBD. If certain foods exacerbate your symptoms, it may be helpful to avoid these foods. However, remember that when you eliminate food, you often eliminate essential nutrients. It is important to reintroduce these foods as soon as possible or seek professional advice from a dietitian to ensure your diet is nutritionally complete.