At a glance
- Keep eating gluten until all your celiac tests are done. Going gluten-free first can make the tests look normal when they are not.
- Testing starts with a blood test (tTG-IgA and total IgA). Most adults then have a gastroscopy with small biopsies to confirm it.
- The treatment is a strict gluten-free diet for life. Avoid wheat, barley, rye and their relatives.
- Ask for a dietitian who knows celiac disease. They can help you find hidden gluten and eat well.
- Avoid cross-contamination: use your own toaster or toaster bags, clean surfaces, and squeeze bottles or your own jars.
- Oats are okay for most people only if they are labelled gluten-free. Add them once you are stable on the diet.
- Parents, brothers, sisters and children of someone with celiac disease should ask their doctor about testing.
- See your doctor and dietitian 3 to 6 months after diagnosis, then regularly, for blood tests and support.
Celiac disease is an immune reaction to gluten. Gluten is a protein in wheat, barley and rye. In people with celiac disease, eating gluten makes the immune system attack the lining of the small bowel. Over time, the lining gets damaged and can’t absorb food well.
Celiac disease is not a food allergy, and it is not the same as being sensitive to gluten. It is a lifelong condition. About 1 in 100 Canadians has it, and many don’t know yet.
What are the symptoms?
Symptoms vary a lot. Some people have many. Some have only a few. Some have none at all.
- Gut symptoms: diarrhea, constipation, bloating, gas, belly pain, heartburn or vomiting
- Other symptoms: tiredness, low iron (anemia), weight loss, mouth ulcers, joint pain, headaches, or tingling in the hands and feet
- Skin: an itchy, blistering rash called dermatitis herpetiformis
- Longer term: thin bones (osteoporosis), and trouble getting pregnant
These symptoms have many other causes too. That’s why testing matters.
How is it diagnosed?
First
Blood test
The first test is a blood test called tTG-IgA (tissue transglutaminase). Your doctor also checks your total IgA. Some people have low IgA, which can make the tTG test falsely normal. In Ontario, OHIP covers both tests if you are eating gluten.If the blood test is positive
Gastroscopy with biopsies
Most adults are referred to a gastroenterologist. A thin, flexible camera is passed through the mouth into the small bowel. The doctor takes several tiny samples, called biopsies. You are usually given medicine to make you relaxed and sleepy. This confirms the diagnosis.
Sometimes, no biopsy. For some children with a very high tTG level, specialists may confirm celiac disease without a biopsy. New European (2025) and British (2026) guidelines say this can also be an option for some adults. The tTG level must be very high, at least 10 times the top of the normal range, and you need to see a specialist. Many adults still have a biopsy. Your specialist will talk with you about what fits you.
Already gluten-free?
Tell your doctor. You may be asked to do a gluten challenge. This means eating gluten again for a few weeks before testing. Celiac Canada describes these options for adults:
- about 1½ slices of wheat bread a day for at least 6 weeks, or
- 2 to 3 slices a day for 6 to 8 weeks
Your doctor will tell you which plan to follow. Children should not do a gluten challenge without a specialist’s advice.
Treatment: a gluten-free diet for life
The only treatment is a strict gluten-free diet. There is no medicine that replaces it yet. Most people feel better within weeks to months. The bowel lining heals over time.
Avoid
- Wheat, including spelt, kamut, durum, semolina and farro
- Barley
- Rye
- Triticale
Also avoid foods made from them, like most breads, pasta, cereals, crackers, baked goods and beer.
Naturally gluten-free
- Rice, corn, potatoes
- Quinoa, buckwheat, millet
- Beans, lentils
- Fruit, vegetables
- Plain meat, fish, eggs
- Milk and most cheese
Hidden gluten and cross-contamination
Read labels every time. In Canada, prepackaged foods must name any wheat, barley, rye, oats or triticale in the ingredient list or in a “Contains” statement. Recipes can change, so check each time you buy.
Gluten can hide in:
- soy sauce (choose tamari or gluten-free soy sauce)
- malt, malt extract, malt syrup and malt vinegar (made from barley)
- beer, unless it is labelled gluten-free
- soups, sauces, gravies and seasoning mixes
- processed meats, veggie burgers and flavoured tofu
- breaded or battered foods, and fries from a shared deep fryer
Cross-contamination means gluten gets into a gluten-free food by mistake. Small amounts matter.
At home
- Use your own toaster, or toaster bags in a shared one.
- Use squeeze bottles, or keep your own jars of butter, jam and spreads.
- Clean counters, pots and utensils before making gluten-free food.
- Wooden boards and spoons can hold crumbs. Keep separate ones for gluten-free cooking.
When eating out, tell staff you have celiac disease, not just a preference. Ask how food is prepared.
What about oats?
Pure oats don’t contain gluten. But regular oats are often mixed with wheat or barley when they are grown and processed. In Canada, oats labelled gluten-free are specially grown and tested to prevent this.
Health Canada says most people with celiac disease can eat gluten-free oats. A small number of people react even to pure oats. Celiac Canada suggests:
- waiting until you are well on a gluten-free diet and your blood test is back to normal
- starting with a small amount, like ¼ to ¾ cup of dry oats a day for adults
- telling your doctor or dietitian, so they can check how you are doing
Family testing
Celiac disease runs in families. Close family members should ask their doctor about testing, even if they feel well.
About 1 in 100
About 1 in 13
Follow-up care
- See your doctor and a dietitian 3 to 6 months after diagnosis. After that, visits are usually every 6 to 12 months until your blood tests are normal, then every 1 to 2 years.
- Blood tests: your tTG level should fall on a gluten-free diet. If it stays high, gluten may be sneaking in. Your team may also check iron and vitamin D.
- Vaccines: experts suggest a pneumococcal vaccine, which protects against a type of pneumonia. Ask your doctor.
- Still unwell? If symptoms don’t settle on the diet, tell your team. The most common reason is hidden gluten. Other causes can be checked too.
Help and money matters
- Celiac Canada (celiac.ca) has guides, recipes, local chapters and help with reading labels.
- Tax credit: the Canada Revenue Agency lets people with celiac disease claim the extra cost of gluten-free foods as a medical expense. You need a letter from a medical practitioner, such as your doctor. Keep your receipts.
Is a gluten-free diet healthier for everyone?
No. If you don’t have celiac disease or another medical reason, there’s no proven benefit. Going gluten-free also makes it harder to test for celiac disease later.
What if I accidentally eat gluten?
It happens to most people at some point. You may get symptoms for hours or days. Don’t panic. Go back to your gluten-free diet. If you are getting symptoms often, see your dietitian to look for hidden gluten.
Sources for this guide
Sources
- Rubio-Tapia A, et al. American College of Gastroenterology guidelines update: diagnosis and management of celiac disease. Am J Gastroenterol 2023;118:59–76. PMID 36602836 Diagnosis by gastroscopy with multiple duodenal biopsies (1–2 bulb, 4 distal); non-biopsy approach in selected children; test first-degree relatives; gluten-free oats recommended with monitoring; dietitian with expertise in the gluten-free diet; pneumococcal vaccine suggested
- Al-Toma A, Zingone F, Branchi F, et al. European Society for the Study of Coeliac Disease 2025 updated guidelines on the diagnosis and management of coeliac disease in adults. Part 1: diagnostic approach. United European Gastroenterol J 2025;13:1855–1886. PMID 40999951 New: conditional no-biopsy diagnosis for selected adults with IgA anti-TG2 ≥10× upper limit of normal, confirmed on a second sample where feasible, limited to adults under 45 for now. Gluten challenge: at least 3 g gluten a day for 6 weeks.
- Penny HA, Shiha MG, Raju SA, et al. The 2026 British Society of Gastroenterology guidelines on the diagnosis and management of adult coeliac disease. Gut 2026 (published online 12 July 2026). PMID 42437688 Rec 6: in symptomatic adults assessed in secondary care, diagnosis can be made without biopsies when IgA-tTG ≥10× ULN; optional, after shared decision-making. Rec 7: gluten challenge 3–6 g gluten daily for at least 6 weeks. GPS 17: pneumococcal vaccination for all adults with coeliac disease.
- Celiac Canada. Gluten challenge (for healthcare professionals). Tests are unreliable on a gluten-free diet. Classic challenge 6–10 g gluten a day (2–3 slices wheat bread) for 6–8 weeks; modified challenge 3 g a day (about 1.5 slices) for at least 6 weeks
- Celiac Canada. Celiac blood test covered by OHIP in Ontario (updated August 2026). After a pilot, tTG-IgA and total serum IgA moved into the Ontario Laboratory Fee Schedule. Covered for insured Ontario residents over 2 years, not previously biopsy-diagnosed, eating gluten, with a requisition from a physician, nurse practitioner or midwife (checked 11 October 2026)
- Celiac Canada. Celiac disease: what is it? Affects about 1% of Canadians; symptoms vary, some people have none; gluten-free diet for life
- Celiac Canada. Management of celiac disease (for healthcare professionals). Follow-up 3–6 months after diagnosis with a doctor and a celiac-skilled dietitian, then every 6–12 months until blood work is normal, then every 12–24 months; iron and vitamin D checks
- Celiac Canada. Oats statement (Professional Advisory Council, 2015). Add only after stable on the gluten-free diet with normal antibodies (may take 6–18 months); start with 25–70 g (¼–¾ cup dry) for adults; rare people react even to pure oats
- Health Canada. Gluten-free labelling claims for products containing specially produced 'gluten-free oats'. Specially produced gluten-free oats may carry a gluten-free claim; most people with celiac disease can eat them
- Health Canada. Celiac disease and the safety of oats (2007, archived). Most people with celiac disease tolerate pure oats; some cannot; clinical follow-up advised
- Canadian Food Inspection Agency. Allergen-free, gluten-free and cross-contamination statements. Gluten sources (barley, oats, rye, triticale, wheat) must be declared on prepackaged foods; gluten-free claim rules
- Celiac Canada. Gluten cross-contamination in the kitchen: what's the risk? Separate toaster still advised; shared condiments and porous wooden tools are risks
- Singh P, et al. Risk of celiac disease in the first- and second-degree relatives of patients with celiac disease: a systematic review and meta-analysis. Am J Gastroenterol 2015;110:1539–48. PMID 26416192 Celiac disease found in 7.5% of first-degree relatives (about 1 in 13)
- Canada Revenue Agency. Details of medical expenses: gluten-free food products (page modified January 2026). Extra cost of gluten-free products over similar products with gluten can be claimed; need a letter from a medical practitioner
This guide is for general education. It can't replace advice from your own care team, who know your health history.