A long term inflammatory disease that can affect any part of the digestive system
Age: onset most common between the ages of 15 and 30
Genetics: sometimes runs in families; more common in certain ethnic groups
Lifestyle: smoking is a risk factor
Crohn’s disease is a long-term illness that usually begins in early adulthood and may cause serious ill health throughout life. Areas of the digestive tract become inflamed, causing a range of symptoms such as diarrhoea, abdominal pain, and weight loss. The disorder can occur in any part of the digestive tract from the mouth to the anus. However, the parts most frequently affected are the ileum (the last part of the small intestine) and the colon (the major part of the large intestine). Inflammation often occurs in more than one part of the digestive tract, with unaffected or mildly affected areas between the inflamed areas.
Crohn’s disease is a relatively uncommon disorder; 30,000-40,000 people are affected in the UK. In Europe and North America, the condition most commonly affects white people, especially those of Jewish origin, and the onset of symptoms usually occurs between the ages of 15 and 30. Crohn’s disease tends to recur despite treatment, and in the majority of cases the condition is lifelong.
The exact cause of Crohn’s disease is unknown. Genetic factors are likely to contribute since about 1 in 10 affected people has one or more relatives with Crohn’s disease or another inflammatory bowel disorder. Smoking may also play a part; smokers are three times more likely to develop Crohn’s disease.
What are the Symptoms
The symptoms of Crohn’s disease vary between individuals. The disorder usually recurs at intervals throughout life. Episodes may be severe, lasting weeks or several months, before settling down to periods when symptoms are mild or absent. The symptoms include:
- Abdominal pain
- Weight loss
- General feeling of ill health
If the colon is affected, symptoms may also include the following:
- diarrhoea, often containing blood
- rectal bleeding
About 1 in 10 people also develop other disorders associated with Crohn’s disease. These other conditions may occur even in mild cases of Crohn’s disease and include arthritis, eye disorders, kidney stones, gallstones and a rash.
Are there Complications?
Complications of Crohn’s disease may include pus-filled cavities near the anus. These cavities can develop into abnormal passages between the anal canal and the skin around the anus, called anal fistulas.
Intestinal obstruction caused by thickening of the intestinal wall is a fairly common complication of Crohn’s disease. Damage to the small intestine may prevent the absorption of nutrients and thus lead to anaemia or vitamin deficiencies. Inflammation of the colon over a long period of time may also be associated with an increased risk of developing colorectal cancer.
How is it Diagnosed?
If your doctor suspects that you have Crohn’s disease, he or she may arrange for a colonoscopy, in which the intestine is examined and tissue samples are taken from affected areas for microscopic examination. If the small intestine is affected, you may have a contrast x-ray of the intestine, known as a small bowel enema study, to look for abnormalities.
Blood tests may be done to check for anaemia and to assess how severely the intestine is inflamed. If your doctor suspects that you have gallstones or kidney stones, you may have imaging tests.
What is the Medical Treatment?
Mild attacks of Crohn’s disease can often be treated with antidiarrhoeal drugs and pain killers. For an acute attack, your doctor may prescribe corticosteroids. As soon as symptoms subside, the dosage will be reduced to avoid the risk of side effects. If your symptoms are very severe, you may need hospital treatment with intravenous corticosteroids. In all cases, once the dosage of corticosteroids has been reduced, your doctor may recommend oral sulfasalazine or mesalazine to prevent recurrent attacks. He or she may also give you an immunosuppressant drug, such as azathioprine.
You may need dietary supplements, such as extra protein and vitamins, to counteract malabsorption. During severe attacks, nutrients may have to be given intravenously.
Many people who have Crohn’s disease need surgery at some stage. The procedure involves removing the diseased area of the intestine and rejoining the healthy ends. However surgery is not usually performed until it is absolutely necessary because further affected regions may develop in the remaining intestine.