How IBD treatment works

The goal: calm the inflammation

Feeling better is important. But in IBD, feeling well is not the whole goal. Inflammation can still be there when you feel fine, and over time it can harm the bowel.

So your team aims for clear goals and checks that you reach them. Doctors call this “treat to target.” In plain words:

1. Short term

   You feel well

   Your bowel habits are back to normal for you, with no blood and little pain.

2. Short term

   Your tests are normal

   Blood and stool tests show no sign of inflammation.

3. Long term

   Your bowel has healed

   A scope or scan shows the lining has healed.

4. Long term

   You can live your life

   Work, school, sleep and family life are not held back by IBD.

If a target is not reached, your team may change the dose, add a medicine, or switch to a new one. Read How we check on your IBD to learn about the tests.

The main types of IBD medicine

Your team will suggest a plan based on the type of IBD you have, where it is, how active it is, and what matters to you. Many people need more than one medicine at some point.

Biologics and advanced pills are mainly used for moderate to severe IBD. Tofacitinib, ozanimod and etrasimod are for ulcerative colitis. Upadacitinib is used for both.

If your IBD is moderate to severe, you may not need to try the older medicines first. Newer guidelines advise starting a biologic or advanced pill early for many people. Ask your team which plan fits you.

5-ASA

5-ASA medicines calm inflammation in the lining of the colon. They are the first choice for mild to moderate ulcerative colitis. They are not usually used for Crohn’s disease, because they don’t work well for it.

Steroids are for short-term use

Steroids such as prednisone work fast. They can calm a flare in days to weeks. But they are not used to keep IBD calm over the long term. Long use can thin your bones and cause other side effects. The aim is always to be well without steroids.

Immunomodulators

These medicines calm the immune system. They help keep IBD quiet, and they are sometimes taken with a biologic so it works better. You will need regular blood tests, especially in the first months. Methotrexate must not be used if you are trying to get pregnant.

Biologics and advanced pills

These are often called advanced therapy. Each one blocks a different signal that drives inflammation:

• Anti-TNF: infliximab, adalimumab, golimumab
• Gut-focused (anti-integrin): vedolizumab
• IL-12/23 and IL-23 blockers: ustekinumab, risankizumab (Skyrizi), mirikizumab (Omvoh), guselkumab (Tremfya). All four are approved in Canada for both Crohn’s and colitis.
• JAK inhibitors (pills): tofacitinib, upadacitinib
• S1P modulators (pills): ozanimod, etrasimod

Some are given as an IV drip in a clinic. Some are shots you give yourself at home. Some are pills. There are now many choices. If one does not work, there are others to try. Read Starting a biologic or advanced pill to learn what to expect.

Biosimilars

A biosimilar is a copy of a biologic medicine. It is made to be highly similar to the original. Health Canada reviews biosimilars to the same strict standards. It expects no real difference in how well they work or how safe they are, even when you switch.

In Canada, there are now biosimilars of infliximab, adalimumab and ustekinumab. Provinces have moved many people from original biologics to biosimilars. In Ontario, people covered by the Ontario Drug Benefit switched from the original infliximab and adalimumab in 2023, and from the original ustekinumab in 2024 to 2025. In some cases, such as pregnancy, people could ask to stay on the original for a time.

Dr. Squirell helped write a review of real-world studies of these switches. People who switched to an infliximab biosimilar did about as well as people who stayed on the original.

Results for adalimumab were also reassuring. Some people found one adalimumab biosimilar stung more when injected.

Your biosimilar may have a different brand name, pen or schedule. Ask your nurse to show you how to use a new pen. If you have private insurance, ask your plan or pharmacist what it covers.

Surgery is a real treatment

Surgery is sometimes the best choice. It is not a sign that you or your treatment failed.

• Ulcerative colitis: Removing the colon can cure the bowel disease. It is a big decision and is usually not the first step.
• Crohn’s disease: Surgery doesn’t cure Crohn’s, but it can treat a narrowing (stricture), a blockage, an abscess (pocket of pus), a fistula (tunnel), or disease that medicine can’t control. After surgery, your team will check for signs that Crohn’s is coming back.

If surgery is an option for you, you can meet the surgeon early to ask questions. That is not a promise to have surgery.

What about food?

No single diet cures IBD or works for everyone. Avoid fad diets. Try to eat a balanced diet with enough protein and calories.

• During a flare, some foods may bother you more. That is OK to adjust for a short time.
• If you have a narrowing in your bowel, your team may ask you to eat less tough fibre (like nuts, seeds and raw vegetable skins). See Fibre.
• For some people with Crohn’s, a liquid nutrition plan can be used as treatment.
• If you are cutting out many foods or losing weight, ask to see a dietitian.

Smoking and Crohn’s disease

If you have Crohn’s disease, smoking makes it worse. People who smoke have more flares and need more medicine.

The good news: quitting helps. In one study, people with Crohn’s who stopped smoking for more than a year had flares about as often as people who never smoked. Ask your family doctor, pharmacist or IBD team for help. Counselling and quit-smoking medicines both work.