At a glance

IBD is a long-term illness. The two main types are Crohn's disease and ulcerative colitis.
IBD is not IBS. It is not contagious. It is not caused by stress or by one food, and it is not your fault.
Call your IBD team if you have new blood in your stool, more trips to the toilet, or belly pain that does not go away. These can be signs of a flare.
Tell your team about sore or swollen joints, a red or painful eye, new skin sores, or yellow skin. IBD can affect more than the gut.
Keep taking your IBD medicine when you feel well, unless your team tells you to change it.
Make a flare plan with your team, so you know what to do and who to call.
With good care, many people with IBD work, study, travel and raise families.

What is IBD?

IBD stands for inflammatory bowel disease. Your immune system (the body’s defence system) attacks the lining of your gut by mistake. This causes inflammation: swelling, redness and sores. IBD is a long-term illness. There is no cure yet, but treatment can calm it down.

There are two main types.

The two main types of IBD

	Crohn’s disease	Ulcerative colitis (UC)
Where	Anywhere from the mouth to the anus. Most often the end of the small bowel and the start of the colon.	The colon (large bowel). It starts in the rectum and can spread up.
Pattern	Patches, with healthy gut in between. It can go deep into the bowel wall.	One even stretch, with no gaps. It affects the inner lining.
Can surgery cure it?	No. Surgery can help a lot, but Crohn’s can come back.	Removing the colon can cure the bowel disease. It is a big choice, and medicine is tried first.

A simple drawing, not to scale. Crohn's disease can cause patches of inflammation anywhere from the mouth to the anus. It is most often at the end of the small bowel and the start of the colon. Ulcerative colitis starts in the rectum and can spread up the colon, with no gaps.

Some people have colitis that doesn’t fit either type. This may be called IBD-unclassified. It is treated in much the same way.

What IBD is not

It is not IBS. IBS (irritable bowel syndrome) changes how the gut works, but it does not cause inflammation or damage. IBD does. You can have both at the same time.
It is not caused by stress. Stress can make your symptoms feel worse. It may help set off a flare. But it does not cause IBD.
It is not caused by one food. No single food causes IBD, and no single diet cures it. Some foods may bother you more during a flare.
It is not contagious. You can’t catch IBD from someone, and you can’t give it to anyone.
It is not your fault. Doctors think IBD comes from a mix of genes, gut germs and things around us. Nothing you did caused it.

Common symptoms

Symptoms depend on where the inflammation is and how bad it is. Common ones are:

Diarrhea (loose stools), sometimes with blood
Needing to rush to the toilet (urgency)
Belly pain and cramps
Feeling very tired
Weight loss or a poor appetite
Fever
A low blood count (anemia)
Sores in the mouth or around the anus

How you feel does not always match what is going on inside. Some people feel fine but still have inflammation. That is why your team checks with tests, too. Read more in How we check on your IBD.

What is a flare?

IBD tends to come and go. A flare is a time when the disease is active and you have symptoms. Remission is a time when it is quiet.

Signs of a flare can include:

More trips to the toilet than is normal for you
Loose stools for more than a few days
Blood in your stool
New or worse belly pain
Feeling more tired, or not wanting to eat

If you think you are having a flare, call your IBD team. Don’t wait for your next visit. It is best to treat a flare early. A flare plan helps you know what to do.

Some signs mean you need help right away. See when to go to emergency.

IBD can affect more than the gut

IBD can cause problems in other parts of the body. These can happen during a flare or when your gut is calm. Tell your team if you notice:

Joints. Pain, stiffness or swelling, often in the knees, ankles or lower back.
Eyes. A red, sore eye. See a doctor the same day if your eye is painful, light hurts it, or your vision is blurry.
Skin. Painful red lumps, or sores that won’t heal.
Mouth. Mouth ulcers.
Liver. Yellow skin or eyes, or dark urine. A rare liver problem called PSC is linked to IBD.
Bones. Thin bones, especially after steroid medicine.
Blood clots. A swollen, painful leg or sudden shortness of breath. IBD raises the risk of clots, mostly during a flare. Shortness of breath or chest pain needs 911.
Mood. Feeling low or worried. This is common, and help works.

How common is IBD in Canada?

Canada has one of the highest rates of IBD in the world. Crohn’s and Colitis Canada’s 2023 report found:

About 322,600

people in Canada live with IBD. That is close to 1 in every 120 people.

More than 11,000

people are diagnosed each year.

By 2035, about 470,000

people are expected to have IBD.

From Crohn's and Colitis Canada's 2023 report on IBD in Canada.

IBD is most often found in young people, but it can start at any age. You are far from alone.

Living well with IBD

IBD is a lifelong condition, and some days are hard. But treatment has come a long way. Many people with IBD have long stretches with few or no symptoms. They go to school, work, travel and raise families.

Things that help:

Take your medicine as planned, even when you feel well.
Go to your check-ups and tests. They catch problems early.
Don’t smoke. Smoking makes Crohn’s disease worse.
Ask for help with mood, sleep or tiredness. These are part of IBD care.
Learn about your treatment. The next guide, How IBD treatment works, explains your options.

Will my children get IBD?

IBD can run in families, because genes play a part. But genes are only part of the story. Things around us matter too. Ask your team if you have questions about your family.

Can I have a baby if I have IBD?

Yes. Most people with IBD have healthy pregnancies. It helps to plan ahead, so your IBD is calm before you get pregnant. See Pregnancy and IBD.

Does IBD raise my risk of colon cancer?

IBD in the colon raises the risk, mostly after many years. People with IBD in the colon may be about twice as likely to get colon cancer. But the risk is still low. Keeping inflammation under control and having check-up colonoscopies when advised both lower it.

Sources for this guide

Sources

Coward S, Benchimol EI, Kuenzig ME, et al. The 2023 Impact of Inflammatory Bowel Disease in Canada: Epidemiology of IBD. J Can Assoc Gastroenterol 2023;6(Suppl 2):S9–S15. PMID 37674492 About 322,600 people in Canada lived with IBD in 2023 (825 per 100,000); projected 470,000 (1.1%) by 2035; over 11,000 new diagnoses in 2023; Canada has among the highest rates in the world; mostly diagnosed in young people.
Windsor JW, Kuenzig ME, Murthy SK, et al. The 2023 Impact of Inflammatory Bowel Disease in Canada: Executive Summary. J Can Assoc Gastroenterol 2023;6(Suppl 2):S1–S8. PMID 37674500 Crohn's and Colitis Canada's 2023 Impact of IBD report: 322,600 Canadians living with IBD.
Crohn's and Colitis Canada. What are Crohn's and colitis? (accessed October 2026). Where each disease occurs; flares and remission; no cure, though removing the colon can be curative for UC; outside-the-gut problems (arthritis, eye inflammation, liver inflammation, blood clots, bone thinning).
Crohn's and Colitis Canada. Frequently asked questions (accessed October 2026). Stress is not a cause but can worsen symptoms; IBD and IBS are not the same (a person can have both); no single diet is the solution.
Crohn's and Colitis Canada. Signs and symptoms (accessed October 2026). Common symptoms list: belly pain and cramping, diarrhea, rectal bleeding, weight loss, fever, anemia, tiredness, mouth and anal sores, urgency.
Crohn's & Colitis UK. Supporting someone with Crohn's or Colitis, edition 2, 2023. Crohn's and Colitis are not contagious; nothing the person did differently would have prevented it.
Murthy SK, Kuenzig ME, Windsor JW, et al. The 2023 Impact of Inflammatory Bowel Disease in Canada: Cancer and IBD. J Can Assoc Gastroenterol 2023;6(Suppl 2):S83–S96. PMID 37674502 Colon cancer risk is higher with IBD and tied to how much inflammation there has been, but the overall risk is still low.
West Hertfordshire Teaching Hospitals NHS Trust. Managing a Crohn's or colitis flare-up (patient leaflet, v3, ratified June 2026). Signs of a flare; outside-the-gut symptoms (joints, eyes, mouth ulcers, skin, tiredness, mood).
Squirell E, Rosenfeld G, Bressler B, Meade S, et al. Pregnant pause? Not for IBD care. Crohns Colitis 360 2025;7:otaf029. PMID 40401215 Prospective cohort of 291 pregnancies in people with IBD: 92.7% live birth rate, preterm and small-baby rates similar to the general population.
Crohn's and Colitis Canada. Are you at risk? (accessed October 2026). IBD comes from a genetic tendency plus things in the environment; smoking raises the risk of Crohn's.
Nistor I, Huang V. Health Maintenance clinical care pathway. Crohn's and Colitis Canada PACE IBD Clinical Care Pathways, version January 21, 2026. IBD raises the risk of blood clots, mostly during active disease; bone thinning with steroids; screen for depression and anxiety; outside-the-gut problems (joints, eyes, skin, liver).
Cosnes J, Beaugerie L, Carbonnel F, Gendre JP. Smoking cessation and the course of Crohn's disease: an intervention study. Gastroenterology 2001;120:1093–9. PMID 11266373 People with Crohn's who quit smoking had fewer flares than those who kept smoking, similar to never-smokers.
East JE, Gordon M, Nigam GB, et al. British Society of Gastroenterology guidelines on colorectal surveillance in inflammatory bowel disease. Gut 2025;75(3):e335023 (published online 30 April 2025). PMID 40306978 Patient summary: people with IBD in the colon may be around twice as likely to develop bowel cancer, but the risk is still low.

This guide is for general education. It can't replace advice from your own care team, who know your health history.

Report a problem with this guide