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Health condition

Ulcerative colitis

Ulcerative colitis is inflammatory bowel disease affecting the colon and rectum in a continuous stretch, causing bloody diarrhoea; a wide range of effective treatments now exists.

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against current NHS and UK specialist society guidance at the time of review.

  • 03

    Current for 2026

    Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.

Key facts

The essentials at a glance.

The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.

  • Typical symptoms: bloody diarrhoea, urgency, cramping and needing the toilet at night

  • Seek urgent help for severe symptoms: more than six bloody stools a day with fever or a racing heart

  • Specialist: a consultant gastroenterologist within an IBD team

  • Treatment options include mesalazine, steroids for flares, immunomodulators, biologics, JAK inhibitors and surgery in selected cases

Understanding the condition

What it is and what happens next.

What causes it, how it is diagnosed, and the treatment routes available in the UK.

What it is and how it feels

Ulcerative colitis inflames the inner lining of the rectum and a variable length of colon in an unbroken pattern. The hallmark is diarrhoea mixed with blood and mucus, with urgency and cramping; flares alternate with periods of remission, and fatigue and joint aches often accompany active disease.

Diagnosis and treatment routes

Colonoscopy with biopsies confirms the diagnosis and maps its extent, with faecal calprotectin used for monitoring. Mesalazine remains first-line for mild to moderate disease, escalating to immunomodulators, biologics or JAK inhibitors when needed; surveillance colonoscopy manages long-term cancer risk, and surgery can cure refractory disease. In many parts of the UK, routine NHS referrals for this kind of problem currently take 20-45+ weeks, whereas an initial appointment with a private consultant is typically available within around two weeks.

Seeing a specialist

Who to see, and how quickly you can be seen.

The specialist for this condition is usually a consultant gastroenterologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.

A quiet reminder

This guide is for information, not medical advice.

Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.

Frequently asked

Common questions about Ulcerative colitis.

Quick, plain-English answers to what people ask us most.

  • What is ulcerative colitis?

    It is a chronic inflammatory bowel disease causing ongoing inflammation and ulceration of the lining of the colon and rectum.

  • What causes ulcerative colitis?

    The exact cause isn't fully understood, but it's thought to result from the immune system reacting abnormally to gut bacteria in people with a genetic predisposition, with environmental factors also playing a role.

  • What are the symptoms of ulcerative colitis?

    Diarrhoea, often containing blood or mucus, abdominal cramping, urgency, and fatigue are typical, occurring in flares interspersed with periods of remission.

  • Is ulcerative colitis serious?

    It can range from mild to severe; while many people manage well with treatment, severe flares can be serious and require hospital admission, and long-standing disease slightly increases the risk of bowel cancer.

  • Is ulcerative colitis hereditary?

    There is some genetic predisposition, with a somewhat higher risk if a close relative has inflammatory bowel disease, though most people diagnosed have no family history.

  • Can ulcerative colitis be cured?

    There's no medical cure, but treatment can control inflammation and achieve long remission; surgical removal of the colon can cure the bowel disease itself for those with severe or treatment-resistant disease.

  • How is ulcerative colitis treated?

    Treatment typically starts with anti-inflammatory medication and steroids for flares, progressing to immunosuppressants or biologic therapies for more persistent disease, with surgery reserved for severe or complicated cases.

  • How long does a flare take to settle?

    With appropriate treatment, many flares improve within a few weeks, though severe flares may need hospital-based treatment and can take longer to fully settle.

  • Ulcerative colitis vs irritable bowel syndrome (IBS) - what's the difference?

    Ulcerative colitis is an inflammatory condition causing visible inflammation and ulceration on colonoscopy, often with blood in the stool, while IBS is a functional disorder without inflammation or structural damage, diagnosed by exclusion of other causes.

  • When should I see a gastroenterologist, and how quickly can I be seen privately?

    See a gastroenterologist for persistent diarrhoea, especially with blood. NHS waits can be lengthy; private gastroenterologists can often see you within about two weeks; severe symptoms need urgent assessment.