Ulcerative Colitis

Knowing more about your Ulcerative Colitis can help you to feel better informed and able to take a more active part in decisions about your treatment.

We hope this booklet will give you and your family and friends a better understanding of Ulcerative Colitis and how it is treated.

Ulcerative Colitis is a condition that causes inflammation and ulceration of the inner lining of the colon and rectum (the large bowel). Inflammation is the body’s reaction to irritation, injury or infection, and can cause redness, swelling and pain. In Colitis, ulcers develop on the surface of the bowel lining and these may bleed and produce mucus.

The inflammation usually begins in the rectum and lower colon, but it may affect the entire colon. If Colitis only affects the rectum, it is called proctitis.

Ulcerative Colitis is one of the two main forms of Inflammatory Bowel Disease, so may also be called ‘IBD’. The other main form of IBD is a condition known as Crohn’s Disease.

Colitis is sometimes described as a chronic condition. This means that it is ongoing and lifelong, although you may have long periods of good health known as remission, as well relapses or flare-ups when your symptoms are more active. Everyone is different – in many people the disease is mild with few flare-ups, while other people may have more severe disease.

At present there is no cure for Ulcerative Colitis, but drugs, and sometimes surgery, can give long periods of relief from symptoms. Research, including work funded by Crohn’s & Colitis UK, is continuing into new treatments to improve patients’ quality of life and eventually find a cure. 

The gut, or digestive system, is a long tube that starts at the mouth and ends at the anus.

When we eat, the food goes down the oesophagus into the stomach, where gastric (digestive) juices break it down to a porridge-like consistency. The partly  digested food then moves into the small intestine, also known as the small bowel. Here it is broken down even further so that the useful nutrients from food can be absorbed into the bloodstream through the wall of the intestine.

The waste products from this process - liquid and undigested parts of food - then pass into the colon, which is also known as the large intestine or large bowel. The colon absorbs the liquid, and the leftover waste forms solid faeces (stools). These collect in the last part of the colon and the rectum until they are pushed out of the body through the anus in a
bowel movement.

In Colitis, parts of the colon and/or rectum become inflamed and sore. Ulcers can develop on the colon lining and these can bleed or produce mucus.

The inflamed colon is less able to absorb the liquid and this can lead to a larger volume of watery stools. Also, because the colon cannot hold as much waste as normal, very frequent bowel movements (six or more a day) may occur.

Ulcerative Colitis symptoms may range from mild to severe and vary from person to person.

They may also change over time, with periods of remission where you have good health and no symptoms, alternating with relapses or flare-ups, when your symptoms are troublesome.

Colitis is a very individual condition - some people can remain well for a long time, even for many years, while others have frequent flare-ups.

Your symptoms may vary according to how much of the colon is inflamed and how severe the inflammation is, but the most common symptoms during a flare-up are:

Diarrhoea. This is often with blood and mucus, and an urgent need to rush to the toilet
Cramping pains in the abdomen. These can be very severe and often occur before passing a stool
Tiredness and fatigue. This can be due to the illness itself, from anaemia (see below), or from a lack of sleep if you have to keep getting up at night with pain or diarrhoea
Feeling generally unwell. Some people may have a raised temperature and feel feverish, with a fast heartbeat
Loss of appetite and loss of weight.
Anaemia (a reduced number of red blood cells). You are more likely to develop anaemia if you are losing a lot of blood or not eating well. Anaemia can make you feel very tired

Everyone is different, and people’s experiences with Colitis vary so widely. Also, much can depend on the severity of your condition and on whether your disease is in a quiet or an active phase.

Some people with Colitis may never have more than mild and infrequent symptoms of diarrhoea and pain, so the illness may not affect their lives very much. Other people have continuous and severe symptoms in spite of medical treatment, and have to adapt their lifestyle considerably.

Our booklet Living with Crohn’s or Colitis looks at some of the challenges of day-to-day life with Colitis. We also have information sheets on Managing Bloating and Wind and Diarrhoea and Constipation, amongst other symptoms.

You are likely to see your GP and specialist doctor on a fairly regular basis if you have Colitis. Many hospitals also have a specialist IBD nurse, who is often the first point of contact for information and support when you are unwell. It can be very helpful to build a good relationship with your healthcare team, so that you can ask about your options and discuss any concerns and worries.

Living with a chronic condition can have both an emotional and practical impact. It can help to have the understanding and support of those around you – your family, friends, work colleagues and employers.

We have information that may be useful, such as IBD and Employment: A guide for employers, and IBD and Employment: A guide for employees, as well as similar publications for students and universities.

Your loved ones may benefit from reading our information on Supporting Someone With IBD: A Guide For Friends and Family. We also run a confidential helpline and over 50 Local Networks throughout the UK, where you can connect with others who have IBD. See the How we can help you section at the end of this booklet for more information.

You may still find that Colitis takes a considerable toll on your emotional wellbeing. In this case, you may find it helpful to talk to a counsellor. Our information on Counselling and IBD has information on how counselling may be able to help.

I have a good relationship with my local hospital and am fortunate to have an excellent IBD nurse. Knowing that I can contact her when I start to experience a flare-up, and knowing that she will help as much as she can, helps to reduce the stress of the situation and speed up treatment.

Andrew person, age 38,
Diagnosed with Ulcerative Colitis in 2007

It is estimated that Ulcerative Colitis affects about one in every 420 people in the UK.

Colitis is more common in urban than rural areas, and in northern developed countries - although the numbers are beginning to increase in developing nations. Colitis is also more common in white Europeans, especially those of Ashkenazi Jewish descent (those who lived in Eastern Europe and Russia).

Colitis affects women and men equally. It tends to develop more frequently in people who don’t smoke or used to smoke than current smokers. However, health professionals consider the risks of smoking greatly outweigh any benefits seen in Colitis, and strongly discourage smoking in anyone, whether or not they have IBD. For more details, see our information on Smoking and IBD.

Although there has been much research, we still do not know exactly what causes Ulcerative Colitis. However major advances have been made over the past few years, particularly in genetics.

Researchers now believe that Ulcerative Colitis is caused by a combination of factors: The genes a person has inherited + an abnormal reaction of the immune system + something triggered in the environment.

Viruses, bacteria, diet and stress have all been suggested as environmental triggers, but there is no definite evidence that any one of these factors is the cause of Crohn’s or Colitis.

Ulcerative Colitis is generally categorised according to how much of the large intestine is affected. The diagram shows the three main types: proctitis, left- sided or distal colitis, and total or pancolitis.


In proctitis, only the rectum (the lowest part of the large bowel) is inflamed. This means that the rest of the colon is unaffected and can still function normally. For many people with proctitis, the main symptom is passing fresh blood, or bloodstained mucus. You may get diarrhoea, or you may have normal stools or even constipation. You may also feel an urgent need to rush to the toilet. Because the inflamed rectum is more sensitive, some people with proctitis often feel that they have an urge to pass a stool, but cannot pass anything as the bowel is actually empty. This is called tenesmus.

In some people, the sigmoid colon (the short curving piece of colon nearest the rectum) may also be inflamed – a form of Colitis sometimes known as proctosigmoiditis. The symptoms are similar to those of proctitis, although constipation is less likely.

Left-sided (or Distal) Colitis

In this type of Colitis, the inflammation involves the distal colon, which includes the rectum and the left side of the colon (also known as the descending colon). Symptoms include diarrhoea with blood and mucus, pain on the left side of the abdomen, urgency and tenesmus.

Total Colitis/ Pancolitis

Colitis that affects the whole colon is known as total colitis or pancolitis. If the inflammation affects most of the colon, but not all of it, it is known as extensive colitis. Extensive and total colitis can cause very frequent diarrhoea with blood, mucus, and sometimes pus (a thicker, more yellow fluid than mucus). You may also have severe abdominal cramps and pain, tenesmus, fever and weight loss. In milder flare-ups, the main symptom may be diarrhoea or looser stools without blood.

In very rare cases, Ulcerative Colitis can cause additional problems in the gut. These complications include:


A stricture is a narrowing of the bowel caused by ongoing inflammation that can make it difficult for faeces (stool) to pass through the colon. Strictures do not usually occur in Colitis, but can sometimes be a sign of bowel cancer.


Very active inflammation in the bowel wall or a severe blockage caused by a stricture may occasionally lead to a perforation (rupture) of the bowel. This makes a hole which the contents of the bowel can leak through. This is a rare medical emergency, symptoms of which include severe abdominal pain, fever, nausea and vomiting.

Toxic Megacolon

When the inflammation is extensive and severe, digestive gases may get trapped in the colon, making it swell up. This is known as toxic megacolon, which can occur in up to one in 40 people with Colitis. Symptoms include a high fever as well as pain and tenderness in the abdomen. It is essential to get treatment quickly for this condition, as surgery may be necessary.


People with Colitis, in particular those who have had pouch surgery (see What about surgical treatment), can in rare circumstances develop fistulas. A fistula is an abnormal channel or passageway connecting one internal organ to another, or to the outside surface of the body. Most fistulas (also called fistulae if more than one) start in the wall of the intestine and connect parts of the bowel to each other, the vagina, bladder, or skin (particularly around the anus).

Fistulas very rarely occur in people with Colitis and are more common in people with Crohn’s Disease. We have more information about living with a fistula

Ulcerative Colitis can cause problems outside the gut. Some studies report as many as one in two people with Crohn’s or Colitis will develop conditions affecting other parts of their body, such as the joints, eyes or skin. These usually happen during a flare-up, but can occur during remission or even before any gut symptoms appear. Your IBD team might use the term extra-intestinal manifestation (EIM) when talking about some of these conditions.


Joint problems, such as swelling and pain (arthritis), affect around one in 10 people with Colitis. The elbows, wrists, knees and ankles, are most commonly affected, but joints in the spine and pelvis can also be affected. Joint problems can come and go – for some people joint problems will get worse during a flare-up, but others may be affected even without any gut symptoms. For information on the diagnosis and treatment of joint problems, and things you can do to help your joints, see our information about Joints.


Colitis can also cause skin problems. A condition called erythema nodosum affects about one in 10 people with Colitis. It causes painful red swellings, usually on the legs, that fade to a bruise-like mark. This condition tends to occur during flare-ups and generally improves with treatment for your Colitis.

More rarely, people with Colitis may develop pyoderma gangrenosum. This starts as small tender blisters, which become painful, deep ulcers. These can occur anywhere on the skin, but most commonly appear on the shins or near stomas. This condition is sometimes, but not always, linked to a flare-up. It's often treated by a dermatologist with topical therapy, but may need treatment with steroids, immunosuppressants or biologics.


Some people with Colitis develop inflammation of their eyes. The most common condition is episcleritis, which affects the layer overlying the white of the eye, making it red, sore and inflamed. Episcleritis tends to flare at the same time as Colitis, and may need anti-inflammatory treatment; sometimes steroid drops are prescribed.

Uveitis, (inflammation of the iris) and scleritis (which affects the white outer coating of the eye) have also been linked to Colitis. These are serious disorders that can lead to loss of vision if left untreated. Tell your doctor or optician if you have any eye irritation, grittiness or inflammation, as they may refer you to an eye specialist. These conditions can usually be treated with steroid drops, but sometimes immunosuppressants or biologic drugs are needed.


People with Colitis are more at risk of developing thinner and weaker bones. This can be due to the inflammatory process itself, poor absorption of the calcium needed for bone formation, low calcium levels from avoiding dairy foods or the use of steroid medication. Smoking also increases this risk. Weight-bearing physical activity, calcium and vitamin D supplements - as well as drug treatment for some people - can be helpful. See our information on Bones and IBD.


About one in 25 people with Colitis get sores or ulcers in the mouth, usually when their condition is active. These sores can be minor and disappear within a few weeks, but can occasionally last for many weeks and may require steroid treatment.


Up to one in three people with Crohn’s or Colitis go through a period of losing more hair than usual. A stressful event or illness can temporarily stop hair from growing. This type of hair loss is called telogen effluvium. Telogen effluvium can be triggered by many things, including severe flares, poor nutrition, iron and zinc deficiencies, some medicines and surgery.

Hair loss often happens months after the trigger, so it may not be obvious what’s caused it. You shouldn’t stop taking a medicine unless your doctor has told you to – your hair loss may have been triggered by a previous flare rather than by your medicine. Very rarely, hair loss may be caused by alopecia areata, an autoimmune condition.

Losing your hair can be very distressing, but for most people it’ll grow back completely as you get better. If you’re losing more hair than usual, speak to your IBD team to check what might be causing it.


Some people with Colitis develop liver inflammation.

A condition called Primary Sclerosing Cholangitis (PSC) affects up to one in 25 people with Colitis. PSC causes inflammation of the bile ducts and can eventually affect the liver cells. Symptoms include fatigue, pain, itching, jaundice and weight loss. Treatment is usually with a drug called ursodeoxycholic acid.

Some of the drugs used to treat Ulcerative Colitis, for example azathioprine and methotrexate, may affect the liver. Changes in treatment may help to reduce this type of complication.

Heart and Circulation

People with Colitis are about twice as likely to develop blood clots in their veins, including DVT (deep vein thrombosis) in their legs. You're more at risk during a flare-up or if you're confined to bed, for example in hospital. Reduce your risk by not smoking, keeping as mobile as possible, drinking plenty of fluids, and wearing support stockings. These precautions are especially helpful when travelling by air, which increases the risk of blood clots for everyone. For more details, see our information on Travel and IBD.

People with active Crohn’s or Colitis may also have a slightly increased risk of cardiovascular disease, including heart attacks and strokes. If you experience chest pain, shortness of breath, or a feeling of numbness, weakness or tenderness in your arms or legs, contact your doctor immediately.


Anaemia is one of the most common complications of Colitis. If you are anaemic, it means you have fewer red blood cells than normal and/or your blood has lower levels of haemoglobin - a protein found in red blood cells that helps carry oxygen around the body. There are several types of anaemia.

People with Colitis are most likely to develop iron deficiency anaemia. This can be caused by a lack of iron in the diet, poor absorption of iron from food, or ongoing blood loss. Some of the drugs used for Ulcerative Colitis, for example sulphasalazine, azathioprine and mercaptopurine, may also cause anaemia.

If the anaemia is mild there may be few or no symptoms. With more severe anaemia, the main symptoms are persistent tiredness and fatigue. You might also develop shortness of breath, headaches and general weakness. Treatment will depend on the cause of the anaemia.

For iron deficiency anaemia you may be prescribed oral iron supplements. Some people with Colitis find that they cannot tolerate iron by mouth, so are given IV (intravenous) iron, which is delivered by injection or an infusion through a drip.

Could my symptoms be IBS?

Irritable Bowel Syndrome (IBS) is a different condition from IBD, although some of the symptoms are similar. Like Crohn's and Colitis, IBS can cause abdominal pain, bloating and bouts of diarrhoea or constipation. However, it does not cause the type of inflammation typical of Colitis, and there is no blood loss with IBS.

Some people with Colitis may develop IBS-like symptoms, for example experiencing diarrhoea even when their Colitis is inactive. These symptoms may need slightly different treatment from their usual IBD symptoms. IBS is more common in people with IBD than in the general population.

If you develop diarrhoea with bleeding and abdominal pain, your doctor may suspect you have Colitis, particularly if you are a young adult or have a family history of Crohn's or Colitis. You will need tests and physical examinations to confirm a diagnosis. See Tests and Investigations for IBD.

You may need to have tests repeated from time to time to check on your condition and how your treatment is working.

Some drug treatments may also require a series of blood tests and, occasionally, x-rays or scans to check for any potential side effects. Your specialist will avoid giving you any unnecessary tests or investigations.

You may need more regular colonoscopies when you have had Ulcerative Colitis for a long time to check for any signs of cancer.

Drug treatment for Colitis aims to reduce symptoms and control flare-ups, and then maintain remission) once the disease is under control. This can mean that you need to take your medication on an ongoing basis, sometimes for many years. It is less likely that you will need only a short course of drugs.

However if your condition is mild and limited to a small part of your colon, you may be able to stop treatment on advice from your doctor if you have been free of symptoms for a few years, and an endoscopy shows disease healing in the gut.

The main types of drugs

The aim of drug treatment for Ulcerative Colitis is to reduce inflammation. The main types of drugs are:

Aminosalicylates (5-ASAs) reduce inflammation in the lining of the intestine. Examples include mesalazine (brand names include Asacol, Ipocol, Octasa, Pentasa, and Salofalk), olsalazine (Dipentum), sulphasalazine (Salazopyrin) and balsalazide (Colazide).

Corticosteroids (steroids) work by blocking the substances that trigger allergic and inflammatory responses in your body. They include prednisolone, prednisone, methylprednisolone, budesonide (Cortiment), hydrocortisone and beclometasone dipropionate (Clipper).

Immunosuppressants suppress the immune system, and reduce levels of inflammation. The main immunosuppressants used in IBD are azathioprine (Imuran), mercaptopurine or 6MP (Purinethol), methotrexate, ciclosporin and tacrolimus. They are often used in patients who relapse when they come off steroids.

Biological drugs are the newest group of drugs used to treat IBD. Anti-TNF drugs, such as infliximab (Remicade, Remsima, Inflectra), adalimumab (Humira) and golimumab (Simponi) target a protein in the body called TNF, or tumor necrosis factor, preventing inflammation. Another type of biological drug is vedolizumab (Entyvio), which works by stopping white blood cells from entering the lining of the gut and causing inflammation.

You can find more information about some of the drugs used for Colitis: Adalimumab, Aminosalicylates (5-ASAs), Azathioprine and Mercaptopurine, Biologic Drugs, Golimumab, Methotrexate, Infliximab, Steroids, Ustekinumab and Vedolizumab.

Other medications may be used to help ease the symptoms of Ulcerative Colitis, rather than reduce the inflammation. However, you should check with your IBD team before using them and they should be used with caution. For detailed information, see Other treatments for IBD.

If your quality of life has been affected by repeated flare-ups and you have not responded well to medication, you may want to consider surgery. For detailed information, see Surgery for Ulcerative Colitis.

About a quarter of people diagnosed with Crohn's or Colitis are children or adolescents at the time they are diagnosed. 

For information on Crohn’s and Colitis in children, see IBD in Children: A parent’s guide, or find out how we support young people and families.

Ulcerative Colitis tends to run in families, and parents with Crohn's or Colitis are slightly more likely to have a child with IBD. However, studies show for most people the actual risk is relatively small.

If one parent has Colitis, the risk of their child developing Crohn's or Colitis is about 2% - that is, for every 100 people with Colitis having a child, about two of the children may be expected to develop Crohn's or Colitis at some time in their lives. This risk is higher if both parents have Crohn's or Colitis.

However, we still cannot predict exactly how Colitis is passed on. Even with genetic predisposition, additional factors are needed to trigger Crohn's and Colitis.

Living with Colitis may mean you have to make some changes. But you can still get the most out of life. And we’re here to help, every step of the way.

You can find out more about:

Living with Crohn’s or Colitis 
• Or see our full range of information

We offer more than 50 publications on many aspects of Crohn’s Disease, Ulcerative Colitis and other forms of Inflammatory Bowel Disease. You may be interested in our comprehensive booklets on each disease, as well as the following publications:

Living With Crohn's or Colitis
Taking Medicines
Managing Bowel Incontinence
Living With a Stoma

Health professionals can order some publications in bulk by using our online ordering system. If you would like a printed copy of a booklet or information sheet, please contact our helpline.

Our helpline is a confidential service providing information and support to anyone affected by Crohn's or Colitis. Our team can:
• help you understand more about Crohn's or Colitis, diagnosis and treatment options
• provide information to help you to live well with your condition
• help you understand and access disability benefits
• be there to listen if you need someone to talk to
• help you to find support from others living with the condition

Call us on 0300 222 5700 
Email helpline@crohnsandcolitis.org.uk
Use our LiveChat 

Crohn’s & Colitis UK Forum
This closed-group community on Facebook is for everyone affected by Crohn's or Colitis. You can share your experiences and receive support from others.

Crohn’s & Colitis UK Patient Panels
IBD Patient Panels, which are supported by Crohn’s & Colitis UK, are groups of people with Crohn's or Colitis who use their perspective as a patient to work with their IBD healthcare team to help improve their hospital services. For more information on patient panels, please read our information leaflet or contact our Patient Engagement Team.

Crohn’s & Colitis UK Local Networks
Our Local Networks of volunteers across the UK organise events and provide opportunities to get to know other people in an informal setting, as well as to get involved with educational, awareness-raising and fundraising activities. You may find just being with other people and realising that you are not alone can be reassuring. Families and relatives may also find it useful to meet other people with Crohn's or Colitis. All events are open to members of Crohn’s & Colitis UK

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Last reviewed: June 2017