Ulcerative colitis

Complications of ulcerative colitis

Primary sclerosing cholangitis

Primary sclerosis cholangitis (PSC) is a common complication of ulcerative colitis that affects about 1 in every 20 people with the condition.

PSC is where the bile ducts, which are small tubes that are used to transport bile (digestive juice) out of the liver and into the digestive system, become progressively inflamed and damaged over time.

PSC does not usually cause any symptoms until the condition has progressed to an advanced stage. Symptoms can include:

  • fatigue (extreme tiredness)
  • diarrhoea (loose, watery stools)
  • itchy skin
  • weight loss
  • chills
  • high temperature (fever) of 38C (100.4F) or above
  • jaundice - yellowing of the skin and the whites of the eyes

There is no direct treatment for PSC but medication can be used to relieve many of the symptoms, such as itchy skin.

Bowel cancer

People who have ulcerative colitis have an increased risk of developing bowel cancer (cancer of the colon, rectum or bowel), especially if the condition is severe or extensive.

The longer you have ulcerative colitis, the greater the risk is:

  • after 10 years the risk of developing bowel cancer is 2%
  • after 20 years the risk of developing bowel cancer is 8%
  • after 30 years the risk of developing bowel cancer is 18%

You will probably be advised to have a colonoscopy every few years to check that no cancer has developed. The frequency of the colonoscopy examinations will increase the longer you live with the condition.

To reduce the risk of developing bowel cancer, you should eat a healthy, balanced diet including plenty of fresh fruit and vegetables. It is also important to take regular exercise, maintain a healthy weight and avoid alcohol and smoking.

Taking your aminosalicylates as prescribed should also help to reduce your risk of bowel cancer.


Osteoporosis is a common complication affecting an estimated 15% of people with ulcerative colitis.

Osteoporosis is a condition that affects the bones, causing them to become thin and weak. The condition is not directly caused by ulcerative colitis, but develops as a side effect of prolonged steroid use.

Though the risks associated with steroid use are well known, in some people, long-term use of steroids is the only way to control the symptoms of ulcerative colitis.

There are a number of medications, such as bisphosphonates, that can be used to strengthen the bones.

You may also be advised to take regular supplements of vitamin D and calcium, as both of these substances have bone-strengthening effects.

Toxic megacolon

Toxic megacolon is a rare and serious complication that occurs in approximately 5% of cases of severe ulcerative colitis. In severe cases of inflammation, gases can get trapped in the colon, causing it to swell. This is dangerous as it can send the body into shock (a sudden drop in blood pressure), can rupture (split) the colon and can cause infection in the blood (septicaemia).

The symptoms of a toxic megacolon include:

  • abdominal pain
  • dehydration
  • high body temperature (40C or 104F)
  • a rapid heart rate

Toxic megacolon can be treated with intravenous fluids, antibiotics and steroids. At the same time, a tube will need to be inserted into your rectum and colon so the gas can be drawn out and your colon decompressed.

In more severe cases, a colectomy will need to be performed.

Promptly treating any symptoms of ulcerative colitis before they become severe can help prevent a toxic megacolon from developing.

Joints are the connection point between two bones that allow movement.
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.
An ulcer is a sore break in the skin, or on the inside lining of the body.
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
The liver is the largest organ in the body. Its main jobs are to secrete bile (to help digestion), detoxify the blood and change food into energy.
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.
If you have a deficiency it means you are lacking in a particular substance needed by the body.
Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Last updated: 27 January 2012

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