Nutrition and IBD

Maintaining a balanced diet can be a significant challenge for people with IBD. Periods of active illness can cause nutritional deficiencies through both loss of appetite and the malabsorption of nutrients in the bowel. Nutritional deficiencies can also occur in people that have had bowel resections, as the part of the bowel that previously absorbed a given micronutrient is missing (e.g., terminal ileum and vitamin B12). It is important to ensure that you are eating a diverse range of foods as this can minimise the risk of nutritional deficiencies, help to maintain a healthy body weight and, for children, to ensure proper growth and development. Common deficiencies in IBD include calcium, vitamin D, vitamin B12 and iron.

It is not uncommon to hear about diets that claim to cure IBD. At present there is not any evidence to suggest diet can cure IBD. People with IBD should also be careful about implementing diets like these as this may involve eliminating certain food groups, which can result in further malnutrition and weight loss. The internet in particular is awash with dubious diets and claims regarding the causes and cures of illness. It is essential that you treat dietary advice with due scepticism and to consider the reliability of information sources. Ask yourself:

  • Is this information from a reliable source?
  • Are these claims justified?
  • Is the claim based on scientific consensus or anecdotal evidence?

If you are considering cutting out a particular food or nutrient, discuss this with your doctor or a dietitian, as they can help assess the potential risks or benefits, as well as suggesting potential replacement sources of a particular nutrient.

You may also come across claims that certain diets or foods can cause IBD. While there have been suggestions that dietary factors could potentially increase the risk of developing IBD, there is not enough evidence to confirm this. The prevailing consensus is that IBD is caused by a complex interplay between genetics and the environment.


What foods should I avoid during a flare?

Although there is no proven dietary cure for IBD, there are some foods that may exacerbate symptoms and others that are easier to tolerate.

  • Dairy: symptoms of abdominal pain, bloating and diarrhea can sometimes be caused by an underproduction of the enzyme lactase. This is called lactose intolerance and is the result of your body having difficulty digesting the sugar (lactose) found in dairy products. Consider lactose-free alternatives to dairy products or other calcium rich/calcium-fortified foods (e.g., tofu, soy milk, calcium fortified cereals).
  • Fatty foods: fat malabsorption associated with small bowel inflammation can exacerbate diarrhea. Avoiding fried or high fat foods may help reduce diarrhea.
  • Fibre: high fibre foods (e.g., grains, nuts, seeds/skins of fruit, vegetables) may exacerbate symptoms during a flare for some people. Lowering fibre intake may some provide symptoms relief. Fibre reduction can be particularly important in cases where there is a stricture (narrowing) of the bowel and the risk of blockage is increased. Do not limit fibre intake long-term (i.e., when you are well) unless instructed to, as fibre is an important part of a nationally balanced diet.
  • Alcohol, caffeine, spicy food: these foods may exacerbate symptoms such as diarrhea during flare-ups.