Ulcerative colitis

Peer reviewed by Dr Ian Arnott, Consultant Gastroenterologist
Next review due March 2019

Ulcerative colitis is a condition that affects your large bowel and rectum (back passage). The lining of these becomes inflamed and ulcers can develop. This can give you diarrhoea, which can come and go. There are a lot of treatment options, which won’t cure ulcerative colitis, but can help to control it and prevent your symptoms from happening.

An image showing a diagram of the large and small bowels

About ulcerative colitis

Ulcerative colitis is the most common type of inflammatory bowel disease – about 146,000 people in the UK have it. Most people develop it between the ages of 15 and 25, or when they’re older – between 55 and 65. But you can get ulcerative colitis at any time in your life. And it’s slightly more common in men than women.

You’ll usually have ulcerative colitis for the rest of your life but your symptoms might follow a relapsing and remitting pattern. This means your symptoms can disappear – sometimes for months or even years – and then flare up again from time to time. But most people have flare-ups at least once a year.

Types of ulcerative colitis

Ulcerative colitis nearly always affects the lowest part of your bowel – your rectum, but it can move up and affect all of your large bowel too. Ulcerative colitis is split into the following types.

  • Proctitis – ulcerative colitis that only affects your rectum.
  • Proctosigmoiditis – inflammation in your rectum and sigmoid colon (the part of your large bowel closest to your rectum).
  • Left-sided colitis – inflammation that begins in your rectum and continues into the left side of your large bowel.
  • Extensive colitis – ulcerative colitis that affects most, or all, of your large bowel.

Symptoms of ulcerative colitis

The symptoms of ulcerative colitis usually come and go. You may have periods without any symptoms, known as remission, and periods when you have symptoms, known as flare-ups. You may find that you feel perfectly well between flare-ups, when you have no symptoms at all.

During a flare-up, the main symptom of ulcerative colitis is diarrhoea, which may have blood or mucus in it. If you have ulcerative colitis, your large bowel and rectum (back passage) can't absorb as much water as usual, which causes this diarrhoea. You may also have lower abdominal (tummy) pain or cramps and need to rush to the toilet. Other symptoms include:

  • feeling extremely tired
  • feeling the need to go to the toilet but not passing anything
  • losing weight
  • feeling generally unwell
  • losing your appetite
  • a high temperature

If you lose a lot of blood through your bowel movements, you may develop anaemia, which can make you feel very tired. There are treatments for this.

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 and inflammation (redness or pain) in your eyes, skin or joints. These problems can occur during a flare-up or while you’re in remission.

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 ask about your medical history too and if any of your family has bowel problems. Your GP will also ask if you’ve travelled abroad recently to check if you might have an infection. 

Your GP may ask you for a sample of faeces, which is called a stool sample. This will help to rule out a bacterial infection. They’ll ask you to have a blood test too.

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

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

  • Faecal calprotectin. This will allow your doctor to rule out other conditions, such as irritable bowel syndrome. You’ll be asked to provide another sample of faeces for this test.
  • Colonoscopy. In this test, your doctor will look at the lining of your large bowel to check for any ulcers or inflammation in your bowel.
  • Flexible sigmoidoscopy. In this test, your doctor will look inside your rectum and the lower part of your bowel.
  • Biopsy. Your doctor may take a small sample of the tissue (a biopsy) from inside your bowel during a colonoscopy or sigmoidoscopy. This will be tested in a laboratory.
  • CT scan or an MRI scan. These will help to show how much of your large bowel is affected by ulcerative colitis.

Treatment of ulcerative colitis

There isn’t a cure for ulcerative colitis yet but there are treatments that can help to settle flare-ups and keep your symptoms away for longer. Remission is when your symptoms disappear for a time.


Medicines can control your symptoms and prevent flare-ups. 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 instructs you to for them to work well. Medicines for ulcerative colitis include the following.

  • Aminosalicylates, such as mesalazine. You can take these as tablets, or as a rectal suppository or enema, which you put into your rectum. You can take aminosalicylates during flare-ups and between them to keep your symptoms away for longer.
  • Steroids, such as prednisolone. You may need to take these if aminosalicylates don’t control your symptoms or if you’re having a flare-up. You can take steroids as tablets, as a rectal suppository or enema. You may also be given steroids through a drip if your flare-up is very severe. Steroids can cause side-effects if you take them for a long time. So your doctor will make sure you take the minimum dose to control your symptoms.
  • Immunosuppressants, such as azathioprine. These are tablets that suppress your immune system. Your doctor may prescribe these if your symptoms haven’t improved with other treatments.
  • Monoclonal antibodies. These are medicines that can recognise and target certain cells. Your doctor may suggest you take a monoclonal antibody called vedolizumab if other treatments haven’t worked for you.

Medicines for severe flare-ups

During a severe flare-up, you could be offered stronger medicines such as ciclosporin or infliximab. You’ll need to go to hospital to have these through a drip in your arm. 

Your doctor will advise you on which treatment is best for you. This will depend on how severe your symptoms are, and you can say what type of medicine you prefer. Always read the patient information leaflet that comes with your medicine. If you have any questions, ask your pharmacist or doctor for advice.


If medicines don't help to improve your symptoms, your doctor may suggest you have an operation to remove your large bowel. This is called a colectomy and is usually considered a last resort – it’s important to discuss all other options with your doctor first. During the operation, your small bowel will be redirected so that your body is still able to get rid of waste products. There are different ways to do this – your doctor will give you advice on what kind of operation is best for you.

  • Proctocolectomy with permanent ileostomy. Your surgeon will remove all of your large bowel, rectum and anus, and close off your back passage permanently. They’ll bring your small bowel to the surface of your abdomen, usually to the right of and below your tummy button. This is called a stoma (ileostomy). You’ll need to attach a bag over the opening, which is called an ileostomy bag, to collect waste.
  • Pouch surgery. Your surgeon will remove your large bowel and rectum. They’ll then make a pouch from the end of your small bowel, and stitch this to your anus. This means your bowel movements can pass through your anus. You may need a temporary ileostomy for a couple of months so that waste can be diverted while the new pouch heals. Your surgeon will then close the ileostomy.
  • Colectomy with ileorectal anastomosis. Your surgeon will remove your large bowel and join the end of your small bowel to your rectum. This means that you won’t have an ileostomy and will be able to pass bowel movements through your anus. This operation isn’t suitable for everyone – it’s usually only an option if you have very mild inflammation in your rectum.

Causes of ulcerative colitis

Doctors don’t yet know exactly why people develop ulcerative colitis but it’s likely that a combination of things are involved. The condition may run in families. If you have a close family member with ulcerative colitis, you’re about 10 times more likely to develop it. Other things, such as getting some types of infection, are also thought to trigger it.

Complications of ulcerative colitis

Ulcerative colitis can lead to a number of complications.

  • You may develop a complication known as toxic megacolon, which is when your large bowel becomes large and full of gas. You might get a high temperature and your abdomen (tummy) may feel sore. If you get these symptoms, seek urgent medical attention. You might need an operation to treat it.
  • Ulcerative colitis can slightly increase your risk of getting bowel cancer. This risk is higher if you’ve had ulcerative colitis for a long time, and if a lot of your bowel is affected. You’ll need to have regular colonoscopies to check for any signs of cancer.
  • Primary sclerosing cholangitis. In this complication of ulcerative colitis, your bile ducts become progressively inflamed and damaged over time. Bile ducts are tubes that connect your liver and gallbladder to your small bowel.

Living with ulcerative colitis

Having ulcerative colitis can have an emotional impact on your life and it’s natural to feel stressed at times. This may possibly trigger flare-ups so if you start to feel stressed, try some techniques to help you relax. One you might find helpful is mindfulness – see Related information to learn more. 

Having a long-term condition like ulcerative colitis can affect your sense of wellbeing too. Flare-ups can be unpredictable so you might feel anxious about going out. To help you overcome these feelings, make a flare-up plan.

  • Before going out, find out where the nearest public toilets are.
  • If you’re worried about having an accident, carry spare clothing in your bag so you can change.
  • Talk to your doctor about what to do when you have a flare-up, as you may need to adjust your medicine.
  • Carry a supply of steroid tablets with you when you travel on holiday (if you’re able to take them). This way, if you have a flare-up, you’ll be able to treat it straight away.
  • Talk to your doctor about other ways to manage your flare-ups. 

Regular exercise will help to relieve tiredness and it can also improve your general health and help to keep your bones strong. This is important because some medicines for ulcerative colitis may make you more likely to develop osteoporosis. See our related information on tips on how to get started with exercise.

If you feel that you need some more support, you could attend a self-help group to talk things through. Internet blogs and online chat forums and message boards can also be a huge source of support.

Frequently asked questions

  • There’s been a lot of research looking into whether certain types of food can cause ulcerative colitis. At the moment, there isn’t any evidence to suggest that any particular foods do. But you may find that some food can make your symptoms worse. 

    Foods that might affect your symptoms include:

    • foods that are high in fibre
    • raw fruit and vegetables
    • spicy foods
    • dairy products, such as milk, cream and cheese 

    Keep a food diary to record what you eat and how severe your symptoms are. This will help you to see if any types of food make your symptoms worse. If you identify any, stop eating them for a while to see if it helps. But don't cut any entire food groups from your diet altogether without having a chat with your GP first. Aim to eat a healthy, balanced diet. Diarrhoea can cause dehydration so make sure you drink enough fluid to prevent this.

    Probiotics, which are found in some yoghurts and milk drinks, may help to control your symptoms or reduce your risk of having another flare-up. But more research needs to be done to find out how effective probiotics are for people with ulcerative colitis.

  • Crohn's disease affects any part of your digestive system from your mouth to your anus whereas ulcerative colitis only affects your large bowel and rectum.

    Crohn's disease and ulcerative colitis are both inflammatory bowel diseases and symptoms of both can include blood in diarrhoea and losing weight. But they affect different parts of your digestive system. Unlike ulcerative colitis, Crohn's disease may be patchy and affect different parts of your bowel.

    Treatment with medicines is similar for both conditions. If you have ulcerative colitis and medicines aren’t helping, you may be able to have an operation to remove your large bowel. If you have Crohn's disease, surgery won’t cure your condition but may help your symptoms.

  • If you have ulcerative colitis, you may be able to help reduce your risk of bowel cancer by taking medicines called 5-aminosalicylates. You can also make changes to your lifestyle, such as keeping to a healthy weight. It’s important to have regular tests to check for any signs of cancer. 

    If you have ulcerative colitis, you have a slightly increased risk of developing bowel cancer. Your risk is greater if a large portion of your bowel is affected or you’ve had severe ulcerative colitis for a long time.

    Studies show that your risk of getting bowel cancer is lower if you regularly take 5-aminosalicylates because these medicines can help to reduce long-term inflammation. 

    Lifestyle changes, such as doing some regular exercise and eating a healthy diet may also reduce your risk of bowel cancer. See Related information for more information on bowel cancer.

    It’s also important to monitor your condition so that any signs of cancer can be spotted early. Your doctor may advise you to have regular colonoscopies to check your bowel for early signs of cancer. They’ll let you know how often you need these. It will depend on how long you’ve had ulcerative colitis, how much bowel is involved and how severe your symptoms are.

About our health information

At Bupa we produce a wealth of free health information for you and your family. We believe that trustworthy information is essential in helping you make better decisions about your health and care. That’s why our content is produced to the highest quality standards. Look out for the quality marks on our pages below. You can find out more about these organisations and their standards on The Information Standard and HON Code websites.

Information standard logo  This website is certified by Health On the Net Foundation. Click to verify.

Learn more about our editorial team and principles >

Related information

Tools and calculators

    • Ulcerative colitis. NICE Clinical Knowledge Summaries., last revised July 2015
    • Ulcerative colitis. BMJ Best Practice., last updated 27 January 2015
    • Infliximab, adalimumab and golimumab for treating moderately to severely active ulcerative colitis after the failure of conventional therapy. National Institute for Health and Care Excellence (NICE), 25 February 2015.
    • Ulcerative colitis: management. National Institute for Health and Care Excellence (NICE), 26 June 2013.
    • Ulcerative colitis. Crohn's and Colitis UK., published November 2013
    • Ulcerative colitis. PatientPlus., last checked 15 July 2013
    • Colonoscopy. Medscape., updated 20 March 2014
    • Flexible sigmoidoscopy. Medscape., updated 1 February 2016
    • Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press., accessed 10 February 2016
    • Vedolizumab for treating moderately to severely active ulcerative colitis. National Institute for Health and Care Excellence (NICE), 5 June 2015.
    • Surgical treatment of ulcerative colitis. Medscape., updated 3 December 2015
    • Ulcerative colitis. American Society of Colon and Rectal Surgeons., accessed 10 February 2016
    • Toxic megacolon. Medscape., updated 3 January 2016
    • Primary sclerosing cholangitis. Medscape., updated 3 January 2016
    • Stedman’s medical dictionary. Lippincott Williams & Wilkins., accessed 10 February 2016
    • Naidoo K, Gordon M, Fagbemi AO, et al. Probiotics for maintenance of remission in ulcerative colitis. Cochrane Database of Systematic Reviews 2011, Issue 12. doi:10.1002/14651858.CD007443.pub2
    • Crohn's disease. PatientPlus., last checked 5 November 2012
    • Colorectal cancer. PatientPlus., last checked 20 January 2015
  • Reviewed by Rachael Mayfield-Blake, Freelance Health Editor, March 2016
    Peer reviewed by Dr Ian Arnott, Consultant Gastroenterologist
    Next review due March 2019

Has our health information helped you?

We’d love to know what you think about what you’ve just been reading and looking at – we’ll use it to improve our information. If you’d like to give us some feedback, our short survey will take just a few minutes to complete. And if there's a question you want to ask that hasn't been answered here, please submit it to us. Although we can't respond to specific questions directly, we’ll aim to include the answer to it when we next review this topic.