Digestive health centre

Digestive diseases: Crohn's disease

What are the symptoms of Crohn's disease?

People with Crohn's disease can experience periods of severe symptoms followed by periods of remission that can last for weeks or years. The symptoms of Crohn's disease depend on where the disease occurs in the bowel and its severity. In general symptoms can include:

• Chronic diarrhoea, often bloody and containing mucus or pus
• Weight loss
• Fever, abdominal pain and tenderness
• Feeling of a mass or fullness in the abdomen
• Rectal bleeding

Other symptoms can develop, depending on complications related to the disease. For example a person with a fistula (abnormal passageway between various organs or tissues) in the rectal area may have pain and leaking discharge around the rectum.

Severe inflammation and obstruction of various parts of the gastrointestinal tract due to swelling and scar formation can cause other problems such as bowel perforation, abdominal distension (swelling), severe pain and fever. This can be life threatening.

Because Crohn's disease is an autoimmune disease (see below), other parts of the body can become inflamed including the joints, eyes, mouth and skin. Gallstones and kidney stones may also develop as a result of Crohn's disease.

Children with the disease may experience decreased growth or delayed sexual development.

What causes Crohn's disease?

The precise cause of Crohn's disease is unknown. However it is likely due to an abnormal response of the immune system. Genes and environmental factors are also believed to play a part.

Who gets Crohn's disease?

Crohn's disease is often inherited. About 20% of people with Crohn's disease may have a close relative with either Crohn's or ulcerative colitis. Jewish people of European descent (Ashkenazi) are at greater risk for the disease.

While Crohn's disease can affect people of all ages, it is primarily an illness of the young. Most people are diagnosed before reaching 30 years old, but the disease can occur in people in their sixties, seventies or later in life.

How is Crohn's disease diagnosed?

A variety of diagnostic procedures and laboratory tests are used to distinguish Crohn's disease from other inflammatory gastrointestinal conditions such as ulcerative colitis.

First your doctor will review your medical history. A specialist called a gastroenterologist may perform a colonoscopy or sigmoidoscopy to obtain bowel tissue for analysis. Other tests your health care provider may order include:

• Blood tests including blood tests.
• Stool samples to rule out infections as the cause of diarrhoea.
• Special X-rays of both the upper and lower gastrointestinal (GI) tract may be arranged as well to confirm the location of the inflammation.