Ulcerative Colitis (intestinal inflammation)

Ulcerative colitis is a form of inflammatory bowel disease in which the lining of the large bowel becomes inflamed and develops ulcers. It usually begins at the rectum and can extend further up the colon. It is a lifelong condition that tends to run in flares, with periods of active symptoms and periods of remission, and during a flare it can mean bloody diarrhoea, cramping and very little warning before you need a washroom.

What ulcerative colitis is, and what it is not

Ulcerative colitis is not irritable bowel syndrome. Both affect the bowel and both can cause pain and urgency, but ulcerative colitis involves visible inflammation and ulceration that a colonoscopy can see and a biopsy can confirm. It is also not caused by anything you ate or by stress, although both can affect how symptoms feel once the condition is established.

It is not the same as Crohn disease either. Ulcerative colitis affects only the large bowel, in a continuous stretch of inflamed lining starting at the rectum. Crohn disease can affect any part of the digestive tract, often in patches, and can involve the full thickness of the bowel wall. Both are inflammatory bowel diseases and both are lifelong, and the difference matters because they are managed somewhat differently.

Signs and symptoms

• Diarrhoea, often with blood or mucus in the stool
• A sudden need to reach a washroom, sometimes with very little warning
• Cramping pain in the lower abdomen, often easing after a bowel movement
• Passing frequent small amounts of stool, including at night
• Tiredness and low energy, sometimes from low iron
• Fever and loss of appetite during a flare
• Weight loss, joint pain, mouth ulcers or eye irritation in some people

The pattern is not steady. Many people have long stretches of remission with few or no symptoms, then a flare that needs treatment, and the extent of bowel involved differs from person to person.

What raises the risk

Some risk factors cannot be changed:

• A family history of ulcerative colitis or Crohn disease
• Genetic background, with Canada having among the highest rates in the world
• Age, with most diagnoses in young adulthood and a second rise after 60
• A previous gut infection, or a course of antibiotics in early life

Others can often be worked on, usually with support from a health care team:

• Smoking status, which alters both risk and the course of the disease and is worth discussing with your care team
• Use of anti inflammatory pain medicines, which can trigger flares in some people
• Diet patterns and vitamin D status, which are under active study rather than settled

How ulcerative colitis is diagnosed in Canada

The diagnosis is confirmed by colonoscopy with biopsies, which shows the pattern and extent of inflammation in the colon and rules out infection and other causes. Before that, blood tests look for anaemia and for inflammation markers such as C reactive protein, and a stool test checks for calprotectin and for infections including C. difficile. Imaging such as CT or MRI enterography may be added. Once the diagnosis is made, monitoring uses stool calprotectin, blood work and repeat endoscopy, including surveillance colonoscopy for colon cancer after some years of disease.

Treatment and day-to-day management

Care in Canada aims to settle a flare, then keep the bowel in remission for as long as possible. Which medicines are available to you can depend on your province and your drug plan. Depending on how much of the colon is involved, how severe the inflammation is and what you have already tried, a health care team may discuss:

• Aminosalicylate medicines, taken by mouth or given rectally as suppositories or enemas
• Corticosteroids used for short periods to settle a flare
• Immunosuppressant medicines, biologic therapies given by infusion or injection, and oral small molecule therapies, all available through Canadian public and private drug plans with varying coverage rules
• Surgery, including removal of the colon with an ileostomy or an internal pouch, for disease that does not respond or for complications
• Supportive care that is part of standard Canadian practice: dietitian input, iron and vitamin replacement, vaccination review, bone health monitoring, colorectal cancer surveillance, and mental health support, since 15% of children with inflammatory bowel disease have clinical depression and 21% clinical anxiety

There is no reliable way yet to predict which medicine will work for which person, so treatment is often adjusted over time. These are decisions for you, your gastroenterologist and your own clinician, and nothing on this page is a recommendation about any of them.

When to talk to a doctor

• Rectal bleeding that is heavy or persistent, or many bloody bowel movements in a day
• Fever with severe abdominal pain, a swollen abdomen, or an inability to keep fluids down, which can signal a severe flare or a complication and needs emergency assessment
• Unintended weight loss, new night time symptoms, or dizziness and breathlessness that suggest significant blood loss, all of which warrant prompt assessment

Why clinical research matters for ulcerative colitis

Even with today’s biologic and oral therapies, a substantial share of people either do not respond, lose response over time, or cannot tolerate treatment, and there is no reliable way to predict which medicine will suit which person. Studies now recruiting are testing new biologic targets and oral small molecules, combination and treat to target strategies, therapies aimed at the gut microbiome including microbiota transfer, and precision approaches that use blood and tissue markers to guide the choice of medicine. Canadian researchers are also studying why the number of new diagnoses is climbing among very young children and among seniors.

Canada has among the highest rates of inflammatory bowel disease in the world and a strong network of research centres, so Canadian sites are often included in international studies. Taking part is voluntary, you give informed consent before anything begins, and you can stop at any time without affecting the care you get from your own doctor. You keep your own care team throughout, and no one can say in advance whether a study will help you personally.

Learn more from Canadian sources

• Crohn’s and Colitis Canada
• Crohn’s and Colitis Canada: 2023 Impact of IBD in Canada report
• Canadian Association of Gastroenterology
• Gastrointestinal Society (Canadian Society of Intestinal Research)