What is it?
This is a summary of information about this condition. For more detailed information we recommend using the NHS Choices website, A link to this can be found in the External Resources tab above.
Ulcerative colitis is a long-term condition, where the colon and rectum become inflamed.
The colon is the large intestine (bowel), and the rectum is the end of the bowel where stools are stored.
Small ulcers can develop on the colon's lining, and can bleed and produce pus.
What causes it?
Ulcerative colitis is thought to be an autoimmune condition. This means the immune system – the body's defence against infection – goes wrong and attacks healthy tissue.
The most popular theory is that the immune system mistakes harmless bacteria inside the colon for a threat and attacks the tissues of the colon, causing it to become inflamed.
Exactly what causes the immune system to behave in this way is unclear. Most experts think it's a combination of genetic and environmental factors.
What are the symptoms and signs?
The main symptoms of ulcerative colitis are:
- recurring diarrhoea, which may contain blood, mucus or pus
- abdominal (tummy) pain
- needing to empty your bowels frequently
Symptoms also include fatigue (extreme tiredness), loss of appetite and weight loss.
The severity of the symptoms varies, depending on how much of the rectum and colon is inflamed and how severe the inflammation is. For some people, the condition has a significant impact on their everyday lives.
Symptoms of a flare-up
Some people may go for weeks or months with very mild symptoms, or none at all (known as remission), followed by periods where the symptoms are particularly troublesome (known as flare-ups or relapses).
During a flare-up, some people with ulcerative colitis also experience symptoms elsewhere in their body. For example, some people develop:
- painful and swollen joints (arthritis)
- mouth ulcers
- areas of painful, red and swollen skin
- irritated and red eyes
In severe cases, defined as having to empty the bowels six or more times a day, additional symptoms may include:
- shortness of breath
- a fast or irregular heartbeat
- a high temperature (fever)
- blood in the stools becoming more obvious
In most people, no specific trigger for flare-ups is identified, although a gut infection can occasionally be the cause. Stress is also thought to be a potential factor.
What tests are used to diagnose it?
A GP can arrange blood or stool sample tests to help determine what may be causing the symptoms. If necessary, they can refer to a hospital for further tests.
What treatments are available?
Treatment for ulcerative colitis aims to relieve symptoms during a flare-up and prevent symptoms from returning (known as maintaining remission).
In most people, this is achieved by taking medication such as:
- aminosalicylates (ASAs)
Mild to moderate flare-ups can usually be treated at home. However, more severe flare-ups need to be treated in hospital to reduce the risk of serious complications, such as the colon becoming stretched and enlarged or developing large ulcers. Both of these can increase the risk of developing a hole in the bowel.
If medications aren't effective at controlling symptoms, or quality of life is significantly affected by the condition, surgery to remove the colon may be an option.
NHS Choices website accessed on 08/10/17
Link to the NHS Choices website available in External Resources
Contains public sector information licensed under the Open Government Licence v3.0.