Crohn’s disease

What is Crohn’s disease?

Crohn’s disease is an inflammatory bowel disease of unknown cause. An autoimmune process inflames the bowel wall, so the bowel stops working properly: nutrients are poorly absorbed and the bowel contents move along with difficulty, causing cramping abdominal pain, weight loss, diarrhoea or constipation. The disease is more common in women and in white populations, and it tends to run in families.

What causes Crohn’s disease?

Crohn’s disease is an autoimmune condition of unknown cause. Certain genetic factors play a part. External factors such as alcohol, smoking and heavy, fatty or spicy food can promote its development.

What are the symptoms?

The disease most often starts at a young age. Common symptoms are cramping abdominal pain and loss of appetite, which quickly lead to weight loss. Most patients complain of bloating. Bleeding in the digestive tract can also occur and may be visible in the stool. Crohn’s most often causes diarrhoea, although a small proportion of patients develop constipation. Nausea and vomiting may also occur.

The inflammation almost always starts in the terminal ileum (the lower part of the small intestine), where it causes ulcers that affect not only the inner lining but the full thickness of the bowel wall. The inflammation can then appear almost anywhere in the digestive tract, including the oesophagus. Repeated chronic flare-ups narrow the bowel, which blocks the passage of its contents and causes pain and sometimes very serious complications (bowel obstruction).

Complications appear as the disease progresses. The most dangerous is bowel obstruction caused by narrowing, which needs urgent surgery. Fistulas often form between sections of bowel, or between the bowel and the abdominal wall (the outside of the body). A fistula is an abnormal channel from the bowel cavity that connects sections of bowel, or the bowel and the outside of the body.

Occasionally the disease also has symptoms outside the bowel, affecting the skin, the eyes or even the joints.

How is it diagnosed?

When typical symptoms appear, the doctor may arrange targeted tests. Blood tests show raised inflammatory markers. Vitamin and iron deficiencies are common and also show up in blood results. Abdominal ultrasound can show a thickened bowel wall, and X-ray or CT scanning is also recommended. Examining the bowel is essential for diagnosis, so a colonoscopy is usually performed, which shows the ulcers and the affected sections of bowel.

What treatments are available?

The first step is usually an anti-inflammatory medicine. If this is not enough, an oral steroid acting mainly within the bowel is used. In more severe cases, a medicine that suppresses the immune system (for example azathioprine) may be needed. Biological therapy is the last step, if the disease does not respond to the earlier medicines. Antibiotics may sometimes also be needed. Because the disease is chronic it cannot be cured, but with these treatments it can be brought into remission for periods of time. At our clinic, eligible patients may be able to take part in a clinical trial of a new medicine from the biological therapy group.