Ulcerative colitis

Expert reviewer, Dr Ian Arnott, Consultant Gastroenterologist
Next review due July 2024

Ulcerative colitis is a long-term condition that causes your large bowel and rectum (back passage) to become inflamed (red and swollen). This causes symptoms like diarrhoea with blood in it, which may come and go. There are lots of treatments that can help control your symptoms.

An image showing a diagram of the large and small bowels

About ulcerative colitis

Ulcerative colitis is one of the main types of inflammatory bowel disease (IBD). The other is Crohn’s disease. In ulcerative colitis, the lining of your large bowel becomes inflamed and develops ulcers. Often, it only affects your rectum (the very end of your large bowel) – this is called proctitis. The affected areas may bleed and produce mucus, which you then pass out when you poo. Crohn’s disease affects any part of your digestive system, from your mouth to your anus.

Most people develop ulcerative colitis either between the ages of 20 and 40, or when they’re older, at around 60. But you can get ulcerative colitis at any time in your life. You’ll usually have ulcerative colitis for the rest of your life. Your symptoms might follow what’s called a ‘relapsing and remitting’ pattern. This means your symptoms can disappear, sometimes for months or even years, and then come back again. This is called a relapse or flare-up. Many people have flare-ups at least once a year, or more frequently.

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Symptoms of ulcerative colitis

Ulcerative colitis symptoms usually come and go. You may have periods without any symptoms (known as remission) and periods when they come back (known as a relapse or flare-up). You may feel completely well between flare-ups, with no symptoms at all.

During a flare-up, your symptoms may include:

  • diarrhoea, often with blood or mucus in it – you may need to rush to the toilet, even at night
  • lower abdominal (tummy) pain or cramps, which may go away after you’ve had a poo
  • feeling like you still need to go for a poo, even when there’s nothing left to pass – (known as ‘tenesmus’)
  • feeling extremely tired – either from the illness itself, lack of sleep, or from losing blood, which can cause anaemia
  • losing your appetite
  • losing weight
  • feeling generally unwell
  • having a raised temperature

There’s a chance that you could develop problems in other parts of your body too. For example, you might get mouth ulcers, skin rashes, red or painful eyes, and painful, swollen joints. These problems usually occur during a flare-up, but can also happen while you’re in remission. You may feel anxious too, and your symptoms can have a significant impact on your quality of life. See our Living with section for more information on this.

If you have any of these symptoms, contact your GP for advice.

Diagnosis of ulcerative colitis

Your GP will ask about your symptoms and examine you. They’ll also ask about your medical history and if any other members of your family have bowel problems. They’ll want to know if you’ve recently travelled abroad, in case your symptoms may be due to an infection. They may ask you for a sample of poo (a stool sample) to check for bacterial infections. It can also be used to look for a marker called faecal calprotectin. This can be raised if you have inflammatory bowel disease. They’ll ask you to have a blood test too.

Depending on the results, your GP may refer you to a gastroenterologist. This is a doctor who specialises in conditions that affect the digestive system.

You might need to have more tests, which can include the following.

  • Colonoscopy. In this test, your doctor inserts a narrow, flexible tube called a colonoscope through your anus and up into your rectum and colon. They’ll use the colonoscope to examine the lining of your large bowel to check for any ulcers or inflammation. They may take some samples of tissue (biopsies) from your bowel too, which will be tested in a laboratory.
  • Flexible sigmoidoscopy. This test is similar to a colonoscopy, but it only looks at your rectum and the lower part of your large bowel. Your doctor can take biopsies during this test too.
  • Gastroscopy. This involves inserting a narrow tube known as a gastroscope into your mouth and down your food pipe (oesophagus). It allows your doctor to look at the upper part of your digestive system. It can help your doctor to work out whether your symptoms may be due to Crohn’s disease, rather than ulcerative colitis.
  • CT or MRI scans. These can give your doctor detailed images of the inside of your body. They can help to show how much of your large bowel is affected by ulcerative colitis.
  • X-ray. You’ll usually only need an X-ray if you have a severe flare-up. It may help to rule out serious problems like toxic megacolon (see our section ‘Complications of ulcerative colitis’).

Treatment of ulcerative colitis

Treatments for ulcerative colitis can control your symptoms and prevent flare-ups. The treatment you have will depend on several things. These include how severe your ulcerative colitis is and how much of your large bowel is affected. You’ll be cared for by a team of healthcare professionals with specialist knowledge of inflammatory bowel diseases (your IBD team).


You may need to take different medicines when you’re in remission and when you’re having a flare-up. It’s really important to keep taking your medicines as your doctor recommends, even if you’re feeling well.

If you have a severe flare-up of ulcerative colitis, you may need to go into hospital urgently. This is because you’ll need specialist care and intravenous medicines (medicines given directly into your vein).

Medicines for ulcerative colitis include the following.

  • Aminosalicylates (also known as 5-ASAs), such as mesalazine. You’ll usually take these as tablets by mouth. You may also have them as a preparation you put into your back passage, in addition to tablets. This is usually for a shorter period of time. This can be as a suppository (a dissolvable capsule you insert through your anus) or enema (a foam or liquid that you apply to your rectum). You can take aminosalicylates during flare-ups as well as when you’re in remission, to help prevent symptoms.
  • Corticosteroids, such as prednisolone. You may need to take these if aminosalicylates don’t control your symptoms when you’re having a flare-up. You can take steroids as tablets by mouth, or as a suppository or enema into your back passage. If you have a severe flare-up, you may have steroids intravenously (through a drip in a vein) in hospital.
  • Immunosuppressants, such as azathioprine. These work by calming down your immune system. Your doctor may prescribe these if you keep needing to take steroids for flare-ups, or after a severe flare-up. You take these by mouth.
  • Biological drugs, such as infliximab. Your doctor may suggest these if you’re having flare-ups and other treatments aren’t working, or you can’t take them for some reason. These drugs are usually given as injections – either into a vein, or under your skin. Some, you take as tablets. If you get on well with them, you may continue taking them when you feel better, to prevent further flare-ups.

If you have any questions about taking your medicines, ask your pharmacist or doctor. Let your doctor know if you’re trying to get pregnant, as some medicines for ulcerative colitis can be dangerous in pregnancy.


Surgery for ulcerative colitis involves removing all, or part of your large bowel. There are several reasons why you may have surgery. These include the following.

  • You’re getting lots of flare-ups and medicines aren’t helping.
  • You keep needing steroids to control your symptoms.
  • Your doctor has identified changes in your bowel during check-ups for bowel cancer (see complications below).
  • You’re having a severe flare-up and you need it as an emergency treatment.

Around 15 in 100 people with ulcerative colitis have surgery within 10 years of being diagnosed. But this number is reducing all the time, as better treatments are available.

Surgery for ulcerative colitis often involves having something called an ileostomy. This is where your surgeon brings the end of your small bowel out to open on the surface of your abdomen (called a stoma). This is so that your body is still able to get rid of waste products. You wear an ileostomy bag over the opening, to collect the waste. You may need to have a temporary or a permanent ileostomy.

Your doctor will talk to you about what kind of operation is best for you and what’s involved. If you’re considering having surgery, it’s important that you discuss all the pros and cons with your doctor first. The most common types of surgery for ulcerative colitis are briefly described here.

  • Pouch surgery (also called ileal pouch-anal anastomosis or IPAA surgery). Your surgeon will remove your entire large bowel – both your colon and rectum. They’ll then make a pouch from the end of your small bowel, and stitch this to your anus. The pouch can store waste products and your bowel movements can pass through your anus as normal. This operation is often done in two or three stages. You may need a temporary ileostomy while the new pouch heals.
  • Subtotal colectomy with ileostomy. Your surgeon will remove most of your large bowel but leave your rectum. You’ll need to have an ileostomy but this may not be permanent. Later on, you may be able to have pouch surgery.
  • Proctocolectomy with permanent ileostomy. Your surgeon will remove all of your large bowel, including your colon, rectum and anus. You’ll need a permanent ileostomy.

Causes of ulcerative colitis

It’s unclear exactly why some people develop ulcerative colitis. It’s thought that it’s probably an autoimmune condition. This means your body’s immune system starts attacking itself. This might be in response to bacteria in your bowel.

Ulcerative colitis runs in families. If you have a close family member with ulcerative colitis, you’re about four times more likely to develop it. Your chance of getting ulcerative colitis may also be affected by your environment and where you live. It’s more common in northern and western Europe.

Complications of ulcerative colitis

Ulcerative colitis can lead to a number of complications.

  • Toxic megacolon. This is when your large bowel becomes enlarged and swollen as part of a severe flare-up. You’ll probably feel very unwell with a high temperature and abdominal pain. It’s uncommon, but if you get these symptoms, seek urgent medical attention. You might need treatment in hospital.
  • Bowel cancer. Ulcerative colitis can increase your risk of getting bowel cancer. The risk is higher if you’ve had ulcerative colitis for a long time, if it’s not well-controlled and if a lot of your bowel is affected. Your doctor may recommend you have regular colonoscopies to check for any signs of cancer. This will usually be from around eight years after you first get symptoms. Keeping your colitis under control may help to reduce your risk of bowel cancer.
  • Primary sclerosing cholangitis. This is a complication affecting your bile ducts. These are the tubes that connect your liver and gallbladder to your small bowel. Primary sclerosing cholangitis causes your bile ducts to become more and more inflamed and damaged over time. You may need to take treatments to control your symptoms if you develop this condition.
  • Perforation (tearing) of your bowel. This can be a complication of a severe flare-up. You might have severe pain, as well as a fever, nausea and vomiting. You should seek urgent medical help if you develop these symptoms.

Living with ulcerative colitis

Ulcerative colitis is a life-long condition that can affect you physically and emotionally. Flare-ups can have a big impact on your social life, education or work. But that doesn’t mean you can’t live life to the full.

Taking care of yourself

It’s natural that living with ulcerative colitis can make you feel stressed at times. Stress can sometimes trigger flare-ups so you may find it helpful to try some relaxation techniques. These may include deep breathing, meditation, yoga and mindfulness.

Regular exercise can also help to give you a boost and make you feel better. It can also improve your general health and help to keep your bones and muscles strong. This is important because some medicines for ulcerative colitis may affect your bone health.

Being prepared

Flare-ups can be unpredictable. To help you be prepared, make a flare-up plan with your doctor or nurse. This may involve adjusting the medicines you take, for instance.

If you feel anxious about going out, it can help to plan ahead. Find out where the nearest public toilets are. You may find it useful to carry a card to help with telling people if you need to use the toilet urgently. If you’re worried about not getting to the toilet quickly enough, carry spare clothing in your bag so you can change. You may also want to carry moist wipes, and plastic bags for soiled clothes.

If you’re going on holiday, make sure you have enough medicine to take with you, including any you need for a flare-up. Take extra medication with you if possible, in case of delays, and a doctor’s note to say what they’re for, especially if you’re flying.

Getting support

Telling your family and friends about your condition and how it affects you may help them to give you the support you need. You’ll also be supported by your IBD team. There will often be a helpline or email you can contact. Keep these to hand, and always seek advice as soon as you need it. Support groups, as well as online chat forums and message boards can also offer a chance to talk to other people having similar experiences. For organisations that can offer reliable information and advice, see our ‘Other helpful websites’ section.

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Related information

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  • Reviewed by Pippa Coulter, Freelance Health Editor, July 2021
    Expert reviewer Dr Ian Arnott, Consultant Gastroenterologist
    Next review due July 2024