Medical advice

How is Crohn’s disease treated?

Treatments for Crohn’s disease aim to reduce or heal the inflammation in the intestine and to deal with the effects of the disease, such as weight loss, and any complications. The inflammation is generally treated with medicines but in some cases surgery is required to cut out very inflamed or narrowed sections of intestine.

Dietary therapy

Many patients ask whether they should change their diet, but there is no proven specific diet for Crohn’s disease. There are, however, diets for certain situations. The most frequent dietary change is a reduction in fibre and indigestible foods which cause pain when there is a narrowing in the intestine (a ‘low residue diet’). Specialised liquid formula diets (‘elemental’ or ‘polymeric’ diets) are also used as treatment in Crohn’s disease, mainly when it affects the small intestine. These diets rest the bowel, improve nourishment and reduce inflammation and are used especially in children where maintaining growth is very important.

Drug therapy

Medicines used to treat Crohn’s disease are mainly directed at the immune system in the intestine. Antibiotics (such as metronidazole) can be helpful, either by reducing the bacteria which ‘drive’ the inflammation or to treat abscesses. Aminosalicylates are a relative of aspirin and are used to treat milder inflammation or reduce the chances of recurrence (for example, after an operation). Steroids (prednisolone, hydrocortisone) are much stronger drugs used to suppress inflammation when the symptoms are more severe. Steroids are very effective (about 8 out of 10 patients have a good response) but have side effects such as weight gain, insomnia,
infection and acne and prolonged use can result in thinning of the bones. Steroids are therefore only used as a short-term measure to get Crohn’s disease under control.

When steroids have been needed, other medicines called immunosuppressive drugs are often used to reduce inflammation over a longer period and allow steroids to be stopped. Azathioprine and 6-mercaptopurine are the most frequently prescribed and around two-thirds of patients have a successful response. Side effects can occur and patients on these drugs therefore need to have regular blood tests. On the whole, however, most patients tolerate the drugs well and they remain the most effective medicine for keeping Crohn’s disease under control. Methotrexate is another immunosuppressive drug, commonly used for treating rheumatoid arthritis. This is usually the next choice if azathioprine or 6-mercaptopurine have failed.

The strongest drug treatment used for Crohn’s disease involves ‘biological therapy’ in which specially developed antibodies are used to block the effects of the molecules that are involved in the inflammation in the gut wall. The best known biological therapies target a substance called tumour necrosis factor (TNF) and are given by a regular intravenous drip or an injection under the skin. Other similar treatments which target different inflammatory mediators are under development. These treatments are very effective but can also have side effects, especially increased rates of infection and allergic reactions, so they are reserved for people with severe Crohn’s disease and when other medicines have not worked.