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 cases.

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

PSC does not usually cause symptoms until it is in an advanced stage. Symptoms can include:

  • fatigue (extreme tiredness)
  • diarrhoea 
  • 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 medications, such as rifampicin, can be used to relieve many of the symptoms, such as itchy skin.

In more severe cases of PSC, a liver transplant may be required.

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 1 in 50. 
  • After 20 years the risk of developing bowel cancer is 1 in 12.
  • After 30 years the risk of developing bowel cancer is 1 in 6.

People with ulcerative colitis are often unaware they have bowel cancer as the initial symptoms of this type of cancer are similar to ulcerative colitis, such as blood in your stools, diarrhoea and abdominal pain.

Because of these issues you will probably be advised to have a colonoscopy every few years to check 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, make sure you 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 aminosalicylates as prescribed should also help reduce your risk of bowel cancer.


Osteoporosis is a common complication affecting an estimated 1 in 6 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.

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

There are several 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.

Read more about the treatment of osteoporosis.

Toxic megacolon

Toxic megacolon is a rare and serious complication that occurs in approximately 1 in 20 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)
  • rupture (split) the colon
  • 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.

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

Emotional impact of ulcerative colitis

Living with a long-term condition that is as unpredictable and potentially debilitating as ulcerative colitis, particularly if it is severe, can have an emotional impact.

In some cases anxiety and stress caused by ulcerative colitis can trigger depression.

Signs of depression include feeling very down, hopeless and no longer taking pleasure in activities you used to enjoy.

If you think you might be depressed, contact your GP for advice.

Read more about treating depression.

You may find it useful to talk to others affected by ulcerative colitis, either face to face or via the internet.

A good resource is the Crohn’s and Colitis UK’s website. This website, operated by the UK’s leading charity for people affected by ulcerative colitis, contains details of local support groups.

The site also contains a large range of useful information on ulcerative colitis and related issues.

You may also find it useful to read our guide to long-term conditions and self care.

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
If you have a deficiency it means you are lacking in a particular substance needed by the body.
The immune system is the body’s defence system, which helps protect it from disease, bacteria and viruses.
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.
Joints are the connection point between two bones that allow movement.
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.
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
An ulcer is a sore break in the skin, or on the inside lining of the body.

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