Nutritional therapy

Nutritional therapy is an essential part of the treatment of Crohn's disease. People with this condition are often malnourished because the inflamed bowel cannot absorb nutrients properly. Low levels of vitamin B12 are particularly likely, especially if the ileumThe last part of the small intestine., the part of the gastrointestinal tractThe gut, which begins at the mouth and ends at the anus. where most of this vitamin is absorbed, has been removed by surgery.

In some cases, nutritional therapy may be used instead of medication, so avoiding the unwanted side effects found with many drugs. It can prolong periods of remission and may reduce the need for surgery.

There are many dietary regimes in use. Any nutritional therapy should only be undertaken with the supervision of your doctor and dietician. A commonly used system consists of:

  • Replacing the regular diet with a liquid enteral feedLiquid food that replaces normal solid food and that can be drunk or administered via a nasogastric tube from nose to stomach or directly into the stomach via a hole in the skin. as the only source of nutrition for a time. Symptoms often settle within two to three weeks, though most doctors recommend staying on the diet for two to three months if possible. Liquid enteral diets may not suit everyone
  • Reintroducing solid foods after this time. They may be introduced one at a time or you may go on an 'exclusion diet'. This is a normal diet that excludes those foods that are known to frequently provoke symptoms (for example, wheat, fatty foods and dairy produce). If any reintroduced foods are followed by a return of problems, these are then excluded from the diet, and replaced with suitable alternative sources of nutrients
  • Testing all foods from your normal diet, then re-testing any that seem to cause problems to make sure they really are to blame.
  • Dietician review to ensure that your diet contains sufficient nutrients. Vitamin and mineral supplements may be recommended if important nutrients are to be excluded long-term.

See the practical help feature, Nutrition in IBD.

Fish oils

Fish oils such as those from salmon, herring and mackerel contain essential omega-3 fatty acids called eicosapentaenoic acidAn essential omega-3 fatty acid found in oily fish. (EPAAn essential omega-3 fatty acid found in oily fish.) and docosahexaenoic acid (DHA), which are important components of any healthy diet.

Some studies have suggested that fish oil supplements may help to maintain remission in Crohn's disease. However, research findings are controversial and not all studies agree.

If you wish to try fish oil supplements, it is sensible to discuss this with your doctor first. If possible, opt for supplements that are enteric-coated. This means that the capsules will not dissolve in the stomach and so reach the small intestineThe section of gut, or gastrointestinal tract, from the stomach to the anus. before the fish oils are released.