This factsheet is about ulcerative colitis

Ulcerative colitis is a disease of the rectum and the large bowel, (otherwise known as the colon). Ulcerative colitis is thought to affect around 1 in 420. The peak age of incidence between 15-25 years old with a smaller peak occurring between the age of 55 and 65 years old. But it can occur at any age.


Ulcerative colitis is one of a group of conditions that are known as Inflammatory bowel diseases, which also includes Crohn’s disease. Inflammatory bowel disease is different to Irritable Bowel Syndrome (IBS), which can cause similar symptoms but does not involve inflammation. The term ‘colitis’ means the large bowel has become inflamed (swollen) and if this becomes severe enough ulcers (open painful sores) may form in the lining of the large bowel.


Causes of ulcerative colitis

We don’t yet know the cause of this condition although most doctors now think it relates to how patients react to the apparently harmless ‘friendly’ bacteria that everyone has in their colon. In most people, the bacteria that live in the colon do not cause any damage and indeed can be quite useful. However, patients with ulcerative colitis don’t see them as being at all friendly and when the lining of the large intestine goes into battle with these bacteria, the result is that the inflammation starts. An enormous research effort is currently under way to find out why patients with ulcerative colitis appear to react badly to bacteria that don’t normally cause any harm in others. There may be other causes which we have yet to discover.

What does Ulcerative Colitis look like?

With UC there is a wide variation in the amount of inflammation from person to person, so that in mild cases the bowel can look almost normal but, when the inflammation is bad, the bowel can look very red and ulcerated. Ulcerative colitis usually affects the rectum, but occasionally there is no inflammation (called rectal sparing). Sometimes the inflammation is limited just to the rectum (called proctitis). However, the inflammation can involve varying lengths of the colon. When the whole large bowel is affected, this is called pan-colitis (total colitis).

How is Ulcerative Colitis diagnosed?

The first steps to diagnosis will include a complete medical history and a thorough visual examination to look for signs of anaemia. The doctors will also examine the abdomen for tenderness (a possible sign of inflammation). If UC is suspected then further tests will be carried out. These will include:

Blood tests: These are to check for anaemia and the level of protein which can measure inflammation known as ESR and CRP tests. In general, the greater the degree of anaemia and the lower the protein level in the blood, the more severe the inflammation is likely to be.

Faecal Calprotectin test: This test examines stools for signs of inflammation and to exclude infection. The most important investigation is to look directly at the lining of the large intestine. This is done using a tube fitting with a camera which passed into the colon via the anus. There are two types of investigations commonly used for ulcerative colitis.

Sigmoidoscopy: This investigation only views the rectum and left hand side of the colon. Patients receive an enema to clear the bowel before the procedure.

Colonoscopy: This is a tube, which is long enough but sufficiently flexible to be passed through your back passage along the whole length of the colon. A colonoscopy will confirm the diagnosis of ulcerative colitis and provide detailed information on the extent and severity of inflammation in the intestine. Patients follow a special diet and take laxatives before the colonoscopy to ensure the bowel is entirely empty and will be offered sedation and pain relief to minimise any discomfort.

For sigmoidoscopy, tiny samples of the bowel lining (biopsies) may be taken, with colonoscopy biopsies are likely to be taken. Biopsies will be analysed under a microscope after the procedure has finished and used to confirm the diagnosis.

How can Ulcerative Colitis affect you?

Although ulcerative colitis varies considerably from person to person, in many cases, the condition does not have much of an impact on daily life, the ability to work or to enjoy an active social life.


The three most common symptoms are diarrhoea, bleeding from the back passage and pain in the abdomen. However, symptoms do differ from one person to the next, so many people may not have all three of these together. For example, some patients may notice that they pass blood when they open their bowels. Others may not have diarrhoea but feel rather constipated. To a certain extent, the symptoms depend on how much inflammation there is and how much of the large bowel is affected by the disease.

For some people, the symptoms can be an annoyance but may be bearable. For others, the condition can really interfere with day-to-day life, which can become organized around visits to the toilet. It is not only just the number of times this can happen each day but the urgency in which some people need the toilet can also be very upsetting. As symptoms are often at their worst in the morning, this can mean the start of the day can be quite an ordeal. Some patients pass considerable quantities of mucus when they open their bowels whilst others can be greatly troubled by wind.

Many patients can just feel tired, not their usual self and they (or their family and friends) notice they have become more stressed. Sometimes there are symptoms outside the abdomen – such as sore eyes, painful joints and skin rashes and unexplained weight loss. Weight loss is a feature of severe disease.

Will Ulcerative Colitis affect me over time?

The effects of ulcerative colitis vary considerably from person to person, based on the nature and severity of their disease. In many cases, the condition does not have much impact on daily life, the ability to work or to enjoy an active social life but does take some getting used to. When it is at an active stage, symptoms such as diarrhoea and abdominal pain often require time away from work, college etc. and can make it difficult to cope going out or even being at home. However, treatment usually makes the symptoms better within days or weeks so normal quality of life can be restored quite quickly. Some severe cases of ulcerative colitis, however, can have a significant impact on people’s lives. This can be due to a weak response to treatment which makes symptom-free remission difficult to achieve and can involve frequent flare ups.


A small number of patients do have complications that relate to ulcerative colitis in their skin, eyes, joints or liver as a result of their disease. When you attend the hospital, you will be monitored to see if any of these complications do develop so that they can be treated. You may have heard that patients with ulcerative colitis run an increased risk of getting bowel cancer so your doctor will keep an eye on your bowel by performing colonoscopy at regular intervals to detect pre-malignant changes in the lining of the bowel at a stage well before any cancer has developed.


What treatment is available for ulcerative colitis?

There are two main stages to your treatment. The first is to bring your condition under control (remission) and the second is long term management of your condition to keep it under control and avoid relapse. There is currently no cure for ulcerative colitis.

Induction of Remission

The medication necessary to do this depends on the severity of your symptoms as will the method of medication delivery. If the inflammation is confined to the rectum (‘proctitis’), it is quite possible the doctor will recommend a medication that you will need to insert into the rectum through the back passage. Although the thought of this can be unpleasant, it can be helpful to appreciate that giving your treatment this way does mean that the therapy is accurately directed right against the inflamed part of your bowel. Treatment can be given as suppositories or as enemas. Enemas can also be useful if the disease involves more of the large bowel than just the rectum alone, but if the inflammation in the bowel is extensive enough to affect more than the left half of the colon, it is also likely that you will be prescribed tablets to take by mouth.


  • Anti-inflammatory drugs: these include aminosalicylates, also known as mesalazine such as Asacol, Octasa Pentasa,  Salofalk and Mezevant. These come in rectal and oral forms and may reduce risk of cancer.
  • Steroids: if the inflammation is more severe then steroids may be used, either in a tablet form or given intravenously in hospital if necessary. Your doctors will choose the preparation they feel is best for you. They are usually extremely safe to use but doctors are rather reluctant for patients to take these drugs long term because of the risk of side effects. However, most patients do get better with these treatments.
  • Immunosuppressive drugs: these are often used to reduce inflammation over a longer period and allow steroids to be stopped. Azathioprine and 6-mercaptopurine are the most frequently prescribed and around two thirds of patients have a successful response. Most patients tolerate the drugs well and they are currently the most commonly used medicine for keeping ulcerative colitis under control. If you are taking these medications you will need regular blood tests.
  • Biologics: in moderate to severe inflammation, biologic drugs such as Infliximab, Adalimumab, Golimumab and Vedolizumab can be helpful to get the disease under control. If remission is achieved, then these drugs can be continued in line with national guidance.

New methods of giving Infliximab and Vedolizumab are being developed, these are pre-filled injection pens that are injected under the skin (subcutaneously). This will make it easier for people as they can be administered by the person with ulcerative colitis or their carers, in the community. This will reduce the need for attending infusion clinics, but the dose will need to be administered more frequently.

Avoiding Relapse

Regular review is important to ensure that you are on the best possible treatment and that your symptoms are well controlled. A good partnership between the patient, the GP and the specialist team can be very helpful. A relapse will be treated with medications as above depending on the inflammation, patient history and previous responses to medication.

Hospital Admission

Doctors try hard to control UC with drugs and medicines. But occasionally this may not work and the patient may have to be admitted to hospital for more intensive treatment and care. Usually this works well and once the inflammation is back under control the patient can go home and resume a maintenance treatment programme.


If the disease still fails to respond to treatment, it is likely that a surgical operation to remove the colon will be considered. This is called a colectomy. Sometimes only a part of the colon needs to be removed; if only half of the colon is removed the operation is called a hemicolectomy. Although surgery can seem a drastic step, it does cure the disease (without a colon, there is no colitis).

Previously colectomy used to mean the fitting of a stoma bag to collect the waste that is usually disposed of via the colon. However nowadays it is usually possible to remove the diseased colon and rectum and then construct a pouch of small intestine that acts very much like the rectum, giving no need for a bag. However, it is important to note that such surgery is usually undertaken over two-three operations and so a stoma is likely for at least a short period of time.


Many patients ask whether they should change their diet, but there is no proven specific diet for ulcerative colitis. Healthy eating guidelines are advised. This consists of a wide variety of foods including fruit and vegetables, cereals, grains, protein-rich foods, nuts and seeds and a reduction or moderation in high fat, particularly animal fat, high sugar foods and processed meats. Some patients have functional bowel symptoms alongside IBD and may benefit from avoidance of specific dietary triggers to manage symptoms. Please ask your IBD team to refer you to a gastroenterology dietitian if you feel that you are having symptoms related to food. Speaking to a dietitian is also helpful if you are worried that you have unintentionally lost weight.


There is research that suggests ulcerative colitis is less common in people who smoke and those who have ulcerative colitis have milder disease and disease progression. It is not known what the reason is for this perceived benefit, but studies also differ in their reporting of the findings. Smoking has significant risk to health, and it is recommended that you stop smoking. As there is a risk of having a flare after stopping within the first 2-5 years it is recommended that you discuss stopping smoking with the IBD team as they may review your treatment to lower the risk of you having a flare-up.


What to ask your doctor?

  • Can I have the details for my specialist team e.g. IBD nurse
    contact details?
  • How often do I need to be seen in clinic?
  • What should I do if I think I’m having a flare?
  • What advice would you give if I’m planning a pregnancy?
  • What advice would you give if I’m travelling abroad?

Where can I get more information?

The National Institute of Health and Care Excellence (NICE) make evidence-based recommendations on a wide range of topics in health, public health and social care. They recommend the most effective ways to prevent and manage specific conditions and to improve health and manage medicines in different settings. You can find their guidelines on UC using the following link. www.nice.org.uk/guidance/NG130

IBD UK is a partnership of 17 patient and professional organisations working together for everyone affected by IBD. They joined forces to develop and publish standards that define what good care should look like for people living with IBD. www.ibduk.org/information-for-patients

IBDesis have created a fantastic video explaining IBD in South Asian languages.

Other support organisations

Crohn’s & Colitis UK

The UK leading organisation supporting people with Inflammatory Bowel Disease, including ulcerative colitis. www.crohnsandcolitis.org.uk

CICRA (Crohn’s In Childhood Research Association)

Is the UK’s only paediatric IBD charity, providing support and information for young sufferers and their families and funding research to find improved treatments and ultimately a cure. www.cicra.org

Ileostomy and Internal Pouch Association

If you have had surgery for UC and have a stoma you can find more information at www.iasupport.org


There is a lot of high-quality research going on in Ulcerative Colitis, but many questions still remain unanswered.

The James Lind Alliance has carried out a Priority Setting Partnership (PSP) on Inflammatory Bowel Disease, which includes Ulcerative Colitis. The PSP has identified 10 research priorities as identified by research users (people affected by the conditions and those who care for them).

NICE (The National Institute for Health and Care Excellence) has listed research questions in its guideline on Ulcerative Colitis. Please note that these guidelines are updated regularly and the research recommendations are likely to change to reflect new evidence available.

Guts UK

Guts UK is proud to fund past and current research into ulcerative colitis, alongside a large number of other digestive diseases. For further information: gutscharity.org.uk

If you wish to take part in research you can contact the National Institute of Health Research ‘be part of research’ page https://bepartofresearch.nihr.ac.uk/

For further information, visit gutscharity.org.uk


Guts UK’s vision is of a world where digestive diseases are better understood, better treated and where everyone who lives with one gets the support they need. We fund life-saving research into diseases of the gut, liver and pancreas.

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