Royal Prince Alfred Hospital
Royal Prince Alfred Hospital
Department of Colorectal Surgery

Colorectal Surgery

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Crohn's disease

Crohn's disease is a type of inflammatory bowel disease (IBD, see Ulcerative colitis) that is characterized by chronic recurrent inflammation of the small or large intestine. Although Crohn's disease occurs most commonly in the last part of the small intestine known as ileum, it can affect any part of the gastrointestinal tract from the mouth to the anus. Most commonly affected parts are: the ileum, the colon, the area around the anus and the remainder of the small intestine.

Who gets Crohn's disease?

Most patients who develop Crohn's disease do so before the age of 30 although a small proportion of patients can develop Crohn's disease later in life. Crohn's disease develops equally in men and women. People with a family history of Crohn's disease have a much higher risk of developing the condition as well, which would support a genetic predisposition. About 20% of patients with Crohn's disease have a family member who also has Crohn's disease.

The cause of Crohn's disease is unclear. Although family history seems important, in many patients, no definite cause can be identified. Smoking seems to be a risk factor and continued smoking after the diagnosis of Crohn's disease plays an important role in exacerbating the symptoms of Crohn's disease.

What symptoms do patients with Crohn's disease have?

The type of symptoms experienced varies depending on the part of the gastrointestinal tract affected and the way in which Crohn's disease affects the bowel. Early on in the disease, Crohn's disease causes ulcers within the bowel. With time, the inflammation can cause either strictures (narrowing) of the bowel or fistula (abnormal communication) of the bowel:

  • Small intestine – pain, nausea, bloating, diarrhea, weight loss
  • Large intestine / rectum – diarrhea, pain, rectal bleeding
  • Skin around the anus – pain, discharge, fevers.

Some patients with Crohn's disease may also develop inflammation in other organs such as the eyes, liver, joints.

These symptoms typically have a remitting and relapsing pattern. In some patients, Crohn's disease can cause complications such as intestinal obstruction from narrowing of the bowel. Some patients may also develop fistula, which are abnormal tunnels that join the affected part of the bowel to a neighboring organ such as the bladder or vagina. Children and adolescence with Crohn's disease may also experience malnutrition and stunted growth if Crohn's disease is poorly controlled.

Tests for Crohn's disease

Crohn's disease can be difficult to diagnose and frequently, a range of tests are necessary to confirm the diagnosis of Crohn's but also to determine if Crohn's disease has caused any complications.

Testing for Crohn's disease typically includes blood tests, x-rays, CT scans, small bowel series and colonoscopy. Colonoscopy in particular is important as it allows your doctor to visualize the lining of your intestine and to take a sample for testing in the laboratory. Your doctor is best placed to advice which test you require.

Treatment of Crohn's disease

Crohn's disease is usually jointly managed by a Gastroenterologist and Colorectal surgeon. Most patients require a medication to suppress the inflammation. This may be achieved by Crohn's specific anti-inflammatory medications such as (5-ASA compounds, steroids) or medications that suppress the immune system such as methotrexate, azathioprine, infliximab or adalimumab.

Some patients may also require surgery. This is usually necessary when patients have developed a complication such as an intestinal obstruction from a stricture or fistula. Surgery for Crohn's disease may require the formation of a stoma.