Crohn's diseaseCrohn’s disease is a chronic illness in which the intestine (bowel) becomes inflamed and ulcerated (marked with sores). Along with ulcerative colitis, Crohn’s disease is part of a group of diseases known as inflammatory bowel disease (IBD).

Crohn’s disease most commonly affects the lower part of the small intestine (ileum), although it can occur in any part of the large or small intestine, stomach, esophagus or even the mouth. It can occur at any age, but it is most common between the ages of 15 and 30.

Symptoms of Crohn’s disease

The symptoms of Crohn’s disease can be unpredictable, with periods of time when the condition flares up, when the disease is said to be active, and periods of time when there are few or no symptoms at all.

Symptoms include:

  • Diarrhoea – which may contain blood or mucus;
  • Painful abdomen (tummy) – this often happens around an hour after eating;
  • Bleeding from your rectum (back passage) – this may lead to anaemia, a condition when there are too few red blood cells or not enough haemoglobin in your blood;
  • Fever;
  • Weight loss;
  • Tiredness;
  • Broken skin, ulcers or abscesses (pus-filled areas) around your anus (if the anus is affected).
  • Active Crohn’s disease may cause other problems such as mouth ulcers, joint pain, red, sore eyes, rashes.

Complications of Crohn’s disease

With severe, long-term inflammation, you may develop complications. The main complications are:

  • Fistula. This is an abnormal connection between two parts of your body. In Crohn’s disease, fistulas usually form between your bowel and your skin
  • Abscess in your abdomen. This is a collection of pus caused by an infection
  • Stricture. This can be caused by scar tissue that builds up after inflammation and may narrow and block your bowel.

If you have Crohn’s disease that affects your colon, you will have a higher risk of developing bowel cancer. One in 20 people with Crohn’s disease will develop bowel cancer in the 10 years after their condition is diagnosed.

Treatment of Crohn’s disease


Medicines are the most effective treatment for most people with Crohn’s disease. Commonly used medicines are listed below.

  1. Antibiotics, for example metronidazole, can help to reduce bacteria in your bowel or treat abscesses. Aminosalicylates, which are similar drugs to aspirin, treat milder inflammation or reduce the chances of a flare-up.
  2. Corticosteroids – can help to reduce inflammation. These are very effective but can only be used for a short time during a flare-up because they can cause serious side-effects.
  3. Medicines to suppress your immune system, for example mercaptopurine or azathioprine, can help to reduce inflammation once you’ve stopped taking corticosteroids.

If you have severe Crohn’s disease and have tried other treatments that haven’t worked, your doctor may suggest medicines called tumour necrosis factor (TNF) inhibitors. Examples of these are infliximab and adalimumab.


There’s no special diet for managing Crohn’s disease but it’s important that you eat healthy, balanced meals. However, if you have any blockages in your bowel which cause abdominal pain, you may want to eat foods that are low in fibre. This is called a low-residue diet. When your Crohn’s disease is active, your doctor may recommend that you have a liquid diet, made up of simple forms of protein, carbohydrates and fats. This is called an elemental diet, and helps your bowel to rest and reduces inflammation.


Surgery may also help if medicines aren’t able to control your condition.

Eight out of 10 people with Crohn’s disease may need to have an operation at some time. If you have a blockage or your bowel has become thickened, then you may need an operation to remove part of your bowel or to widen it.