Ulcerative colitis

Last updated:

Reviewed by:

Dr Bryony Henderson

, Lead GP at Livi

Medically reviewed

Ulcerative colitis happens when the bowel and rectum become inflamed over a long time. This causes ulcers to form. Find out why it happens and what changes you can make to your lifestyle to improve your bowel health.

What is ulcerative colitis?

Ulcerative colitis is an autoimmune condition and is caused when the body's own immune system attacks healthy tissue in the bowel and rectum. This results in inflammation which can lead to the formation of ulcers. Ulcerative colitis is a type of inflammatory bowel disease (IBD).

What are the symptoms of ulcerative colitis?

For many people, ulcerative colitis can have a massive impact on their life. Common ulcerative colitis symptoms are:

  • Diarrhoea containing pus, mucus or blood, which happens regularly

  • Pain in your tummy

  • A frequent, urgent need to poo

  • Fatigue

  • Loss of appetite

  • Weight loss

Symptoms and their severity can depend on the amount of inflammation in your bowel and rectum.

Ulcerative colitis is a long-term condition. Some people may have no symptoms or only have very mild symptoms for several weeks or months. This can then be followed by a flare-up where symptoms can be particularly severe. Some common ulcerative colitis flare-up symptoms are:

  • Arthritis, resulting in joints that are painful and swollen

  • Red, sore and swollen skin

  • Mouth ulcers

  • Eyes that are red and irritated

In severe cases, where you have to poo more than 6 times a day, you may also have symptoms of: 

  • A fast or irregular heartbeat

  • Fever (high temperature)

  • Shortness of breath

If you experience any of the ulcerative colitis symptoms above, speak to a doctor or call NHS 111, as you may need hospital treatment.

What causes ulcerative colitis?

Doctors aren't exactly sure what causes ulcerative colitis. But it's generally thought to be caused by an autoimmune condition, where your body attacks healthy tissue by mistake. This results in redness and swelling in the bowel and rectum.

Other causes may include:

  • A viral or bacterial infection

  • Genetics - one in 4 people who develop ulcerative colitis have family members that also suffer from it 

  • Environmental factors - air pollution, medication and certain diets may also be linked to cases of ulcerative colitis

How can I reduce my risk of ulcerative colitis?

Certain lifestyle factors might increase your risk of ulcerative colitis.  Simple changes that can make the symptoms less severe include:

  • Eating smaller meals

  • Eating a low-fibre diet

  • Drinking plenty of fluids (but be careful to avoid caffeine, alcohol and fizzy drinks)

  • Reducing stress

  • Keeping a food diary to see what food potentially causes flare-ups.

Who is more likely to be affected by ulcerative colitis?

The risk factors that increase your chance of having ulcerative colitis are:

  • Age – the condition is most commonly diagnosed in 15–25-year-olds

  • Race – it's most common in white people of European descent and black people

Both men and women are equally affected by ulcerative colitis.

How is ulcerative colitis diagnosed?

If you think you're having ulcerative colitis symptoms, you should speak to a doctor. Some tests they might recommend include:

  • A physical examination for signs of tenderness in your tummy

  • An X-ray or CT scan 

  • A blood test to check if you're anaemic (don't have enough red blood cells in your blood)

  • A sigmoidoscopy, which involves a thin, flexible tube with a camera at one end being passed into your rectum in order to examine your lower bowel. The doctor may also take a small sample from your bowel to test it (this is called a biopsy). 

  • A colonoscopy, which is similar to a sigmoidoscopy but involves your entire bowel being examined

How is ulcerative colitis treated?

The treatment you have will depend on how severe your ulcerative colitis is. 

Treatment options may include:

  • Aminosalicylates (ASAs) – medication to reduce inflammation and allow damaged tissue to heal

  • Corticosteroids – a more powerful medicine to reduce inflammation

  • Immunosuppressants – to minimise the activity of your immune system

  • Colectomy – surgery to remove part of your bowel (colectomy)

  • Ileostomy – surgical procedure to divert the small intestine through a hole in your tummy and use a special bag to collect waste materials

  • Ileoanal pouch (also called a J-pouch) – an internal pocket that connects to your anus and allows you to poo as normal

In most cases, mild to moderate ulcerative colitis problems can be treated at home. 

Are there any ulcerative colitis complications?

In rare cases, ulcerative colitis complications can occur. It’s better to speak to a doctor as soon as you start having symptoms. 

Complications may include:

  • Damage to the bile ducts inside the liver (primary sclerosing cholangitis)

  • Bowel cancer

  • Stunted growth and development in children and young people

  • Weakening of the bones (osteoporosis) caused by taking corticosteroids to treat the condition

  • Toxic megacolon – where inflammation in the bowel results in trapped gas, causing it to become swollen and enlarged. In severe cases, this can cause the bowel to split open and potentially lead to a blood infection (sepsis)

When should I speak to a doctor?

If you have any of the symptoms above, book an appointment to speak to a healthcare professional. They will discuss your symptoms with you and help to determine a potential treatment or management path. 

Last updated:
Reviewed by:
Dr Bryony Henderson, Lead GP at Livi