CMAJ Podcasts

Diagnosis and management of celiac disease

• Canadian Medical Association Journal

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Celiac disease affects between one and two percent of Canadians, yet many patients wait years before receiving a clear diagnosis. On this episode of the CMAJ Podcast, the hosts speak with two contributors to the CMAJ review article Diagnosis and management of celiac disease about the condition’s diverse clinical presentations, appropriate testing strategies, and the practical realities of long-term dietary management.

Jedid-Jah Blom, a registered dietitian at the McMaster Celiac Disease Clinic and researcher at the Farncombe Family Digestive Health Research Unit at McMaster University, shares her own experience being diagnosed and living with celiac. She explains how patients must identify hidden gluten sources in ingredients like dextrin and malt, and why cornmeal or corn flour products may be contaminated. Blom outlines the risks of cross-contamination and dining out challenges, emphasizing whole gluten-free grains over processed products that lack fortification.

Dr. Maria Ines Pinto-Sánchez, a gastroenterologist at Hamilton Health Sciences and director of the Celiac Clinic at McMaster University, explains why celiac is called a chameleon disease. She notes that about 30 percent of patients present with gastrointestinal symptoms, while others may have brain fog, fatigue, or anemia. She describes how TTG antibodies plus total IgA are used for screening, with positive results requiring endoscopy and biopsies for confirmation. Dr. Pinto-Sánchez emphasizes that patients should not start a gluten-free diet before testing. She discusses ongoing monitoring including TTG levels, bone density, and nutrient deficiencies.

For physicians, the discussion highlights the need for a low threshold when testing TTG antibodies in patients with unexplained fatigue, brain fog, or gastrointestinal symptoms. Both guests stress the importance of completing diagnostic testing before patients begin a gluten-free diet and arranging early dietitian referral.

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Dr. Blair Bigham:

I'm Blair Bigham.

Dr. Mojola Omole:

I'm Mojola Omole. This is the CMAJ podcast.

Dr. Blair Bigham:

So, Jola, today we are talking about celiac disease, which is way more common than I thought it was, even though a very good friend of mine suffers immensely from it. But you're a general surgeon. I think you see this more than I do as an emergency doc.

Dr. Mojola Omole:

I do.

Dr. Blair Bigham:

What do you think?

Dr. Mojola Omole:

I would definitely say that the diagnosis of it has been going up, and oftentimes, you know, the classic things that you would, you know, when you talk to patients, they're coming in for IBS, and so, you know, can you scope them? And so you're going through it. Do certain foods bother you? And they actually don't have, like, what you would think would be the usual foods. And I routinely biopsy. I think most of us do routinely biopsy in the duodenum. And then the diagnosis of celiac, more and more has been coming back positive.

Dr. Blair Bigham:

So that is one of the reasons we are going to talk about a review article from CMAJ titled Diagnosis and management of celiac disease. It is actually a compelling read. It's very concise and very meaty. And we're going to take a look at what not only the experts say, but also what a patient says. Coming up, we're going to speak to two authors of the review article, one of whom has celiac disease herself. Jedid-Jah Blom is a registered dietitian at the McMaster Celiac Disease Clinic and researcher at the Farncombe Family Digestive Health Research Unit at McMaster University. Dr. Maria Ines Pinto-Sánchez is a gastroenterologist at Hamilton Health Sciences. She is director of the Celiac Clinic at Mac. Ines and Jedid-Jah, thank you so much for joining us today. Jedid-Jah Blom Thank you very much for having us. Jadid, let's start with your story. You're a registered dietitian, but also you were tested for celiac disease. That was more than a decade ago. Tell us about that. Jedid-Jah Blom Yes. So one of my first-degree family members was diagnosed with celiac disease more than 10 years ago. And they told me to get myself tested at the time. So I did the tissue transglutaminase blood test, and it was negative at the time. Then 10 years after that test, I ended up having an infection and I had to take antibiotics. And then suddenly, a few months after that, I started having digestive symptoms, abdominal pain, bloating, constipation, IBS-type symptoms, I thought. And on top of that, I started feeling very tired after I had my lunch. I could barely keep my eyes open, like I needed matchsticks to keep in between my eyelids. So I ended up going to the family doctor. I got my iron levels checked and my thyroid tested. And my iron came back borderline low. My thyroid was normal. So then I started an iron supplement. And then as the months went on, I started to develop cognitive issues. I had difficulty concentrating. My speed of thinking went down. Interpreting data, even my memory, I could not memorize very well. And it felt like I was a bystander in conversations, like I was just listening in on the conversation. The information went in on one ear and out the other side. The physical fatigue continued. I was exhausted at 9 p.m. in the evening, I felt so tired I had to go to sleep. I even tried biking. I thought maybe I should incorporate some physical activity. But holding onto the steering of the bike, I even could not get a good grip. I felt like I couldn't keep my balance. It was shaky. So I ended up putting my bike back into the garage. Then I went back to see my doctor one year after those digestive symptoms had started. And then they saw in my family history that I had celiac disease. So again, I did the anti-tissue transglutaminase blood test. And then it came back higher than 250. Then they told me to start a gluten-free diet right away. It took a full year for you to get diagnosed from when you started having those symptoms after the antibiotics. How long after that until your symptoms improved? Jedid-Jah Blom Yes, so basically I started the gluten-free diet about a month after that. Because as I learned from Dr. Pinto Sanchez, I had to do an endoscopy still to get my celiac disease confirmed. So then I was finally sure that it was celiac disease. Then I started the diet. And three weeks into the strict gluten-free diet, I noticed a significant improvement in the abdominal pain and the bloating. The fatigue slowly started to get better. The brain fog and the anxiety, I also had a lot of anxiety. Those took about two years to fully recover. And so I ended up taking some cognitive behavioral therapy. And I found it was very helpful. In terms of the diet, I was very excited in the beginning because I could try new gluten-free products that I'd never tried before. So I started very happy as a dietitian myself. I get to try all these new foods. But then slowly you start to become confronted with the fact that this is a lifelong disease that you're carrying with you. And whenever you are exposed to food, even when you're outside your home, right, you have to tell a stranger that you have celiac disease. And so it's disclosing some personal information that you may not even want to. Even my kids, you know, they keep telling me, Mom, when can you start eating gluten again? So I have to talk with them and say, well, until we have a medication, then I will have to keep on this strict gluten-free diet lifelong. But yes, it did resolve in the end. And I'm very happy where I am right now. The impact of this on you seems pretty self-evident. Ines, why did you think it was important for physicians to focus on this in 2025? What was your experience that had you bring this to light?

Dr. Maria Ines Pinto-Sánchez:

Yeah, so I think it's very important. Jadid touched with her story, she touched on many aspects why it's so important to focus on this celiac disease. First is the delay in diagnosis of celiac, right? So Jedid was lucky that she was diagnosed one year after her symptoms started. But the majority of people are struggling for years and years. And in Celiac Canada, they did a survey for thousands of people with celiac disease. And the average of diagnosis of celiac is 12 years. So that's first. So we should, as physicians, be more aware of what is celiac disease and also how celiac is called a chameleon. A chameleon. Because it can present in many different ways. So as Jadid has told her story, she was presenting, initially she didn't have much symptoms. And then suddenly she took antibiotics and then she got IBS symptoms, right? But yes, so some people present with gastrointestinal symptoms, but many others, they don't have gastrointestinal symptoms, right? So, and I heard many stories of patients say, oh, my doctor didn't want to do a test on me because I was normal weight. I was not underweight. So this probably means misunderstanding on clinical presentation of celiac disease can lead to delays in diagnosis. So it's first to be aware that celiac can manifest in many different ways and even can present without symptoms. So if the person has a high risk population or has a family member, that should prompt the diagnosis. And the other aspect is that in Jedid's case, she touched another important point. Initially, her TTG was negative, but she had a family member. And I wish she had tested soon after that. Usually what is recommended is to test every three to five years, right? So if you have a family member, you are the highest risk population. So keep an eye on that. Even if a family member doesn't have any symptoms, is to check for celiac disease. And if it is negative, is to start thinking that it will not be negative forever. It may not be negative forever. So to keep an eye on that.

Dr. Blair Bigham:

I want to try to break this down and walk through things one step at a time. Let's start with the incidence. How common is it to see celiac disease in the Canadian population?

Dr. Maria Ines Pinto-Sáanchez:

So it's between one or two percent. And the incidence is growing, right? And this is not only in Canada. It's in the world. Celiac disease rates are increasing. But so far right now, you can see one, 1.5 percent of population is anticipated to be celiac. And this is similar rates around the world.

Dr. Blair Bigham:

Before we get into the diagnosis, what symptoms should prompt physicians to test for celiac? What are some of the red flags that should make us go, huh, this could be celiac?

Dr. Maria Ines Pinto-Sáanchez:

So first, celiac can manifest without symptoms. So not only 30 percent of people with celiac, they present with gastrointestinal symptoms. And when gastrointestinal symptoms are present, it's not just diarrhea. It can be constipation as well. So if someone has constipation, it can be a manifestation of celiac. Most commonly people present bloating, distension, changes in bowel movement like diarrhea, constipation, IBS symptoms. But again, this doesn't happen in everyone. And keep in mind that if your patient doesn't have gastrointestinal symptoms, even if they have foggy mind, tiredness, these can be symptoms of celiac disease as well.

Dr. Mojola Omole:

Just a quick question. I'm a general surgeon, so I do quite a bit of endoscopy also. But I'm just thinking that if someone doesn't have GI symptoms, but they're coming in with brain fog and cognitive slowing, how would a family doctor be able to connect that? Could this be celiac?

Dr. Maria Ines Pinto-Sáanchez:

Just to clarify, I will say it's important to rule out celiac if any of these symptoms are present, right? And the way that you rule out celiac is not through endoscopy, is by testing TTG antibodies. So if I will say to be very open and very low threshold to test for TTG antibodies, now TTG is covered everywhere. So it's a cheap test, very relatively cheap test. So it can be just requisition to any lab. And then it says TTG antibodies and make sure that the patient is developing total IgA because there is one or two percent of IgA deficiencies in the general population. So TTG IgA plus total IgA, that's the test for screening for celiac.

Dr. Mojola Omole:

So basically, when you order your blood work, keep it broad and make sure you put celiac in your differential diagnosis if someone has vague symptoms like brain fog, fatigue, that can be pinpoint to something. Correct, correct. Perfect.

Dr. Maria Ines Pinto-Sáanchez:

And if someone has a family member, first family member with celiac disease, OK, so those first family members are the highest risk population. So 15 percent prevalence of celiac disease within first family member, which is 15 times more than the general population. Right. So it's in those cases, even if they don't have any specific symptoms, it is recommended to check for celiac.

Dr. Mojola Omole:

And with those people, it's still blood work still, right?

Dr. Maria Ines Pinto-Sáanchez:

Still blood work. OK. And if the blood work is positive, then that prompts endoscopy. If the blood work is negative, it's to keep an eye on that. Because again, as Jadid presented in her story, she's not the only one. It's sometimes that celiac can manifest and can present at any time in life. Right. So it's possible. And I have many patients in a similar situation that TTG was negative for years and then it becomes positive. And this is because celiac disease is an immune mediated condition that, of course, everyone is born with the genes, but not everyone with the genes will develop celiac because something needs to trigger celiac disease and something needs to trigger that immune reaction. Right. So that something can happen any time in life. Right. So that's why we have people diagnosis at different ages and not just, you know, in childhood.

Dr. Blair Bigham:

Once it's diagnosed, and we'll talk more about diet in a minute. But what do physicians also need to be monitoring for on a longer term basis?

Dr. Maria Ines Pinto-Sáanchez:

So that's a very important point. And I heard many times that my patients come and say, oh, I was diagnosed 20 years ago. Nobody checked any TTG again and I was told to go gluten free and that's it. Right. And it's important to first monitor that the celiac activity is under good control. And that is a combination of serology. So, the TTG markers, the recommendation is to repeat once. Once we diagnose celiac disease is to repeat those markers every six months or so or six to nine months until the celiac is under good control. Once the patient's TTG become negative and the patient knows how to do the diet, then those markers can be repeated every year or every two years just to keep an eye. And this is because, as I mentioned, not everyone perceives when they are exposed to gluten. And it's very common to have an inadvertent exposure to gluten. So you want to detect any activation of celiac disease through those markers. Right. So that's one. And then that's a celiac activity. Another important aspect is related to complications of celiac disease. We're monitoring symptoms, of course, which sometimes are not related to celiac disease, but we monitor those. But also to prevent complications. So what are the complications? So we monitor bones. That's important. And what is, again, it's that there are no very good consensus, but most recommendations are to check bones at baseline and to have a bone density scan done and see if the bone density is normal, then you don't need to monitor that. Just follow regular recommendations if the celiac is under good control. But if there is osteopenia or osteoporosis, so there are recommendations that we give to increase calcium in your diet, to increase vitamin D, to increase exercise, and then to keep an eye on those, on that bone density every two or three years to repeat another bone density to see if that improves. In most of the cases, when the celiac is under good control, the bones improve as well because the absorption improves, the immune activity decreases. So another very important aspect is nutrients. We are seeing a lot of nutrient deficiencies, and we did study ourselves in our clinic and 60% of patients have an associated nutrient deficiency even during the follow-up. And the most common nutrient deficiencies are iron, zinc, vitamin D by far. Almost 50% of our patients on a gluten-free diet have low zinc and that can impair other aspects, other nutrition. And so it's important to monitor some nutrients as well. So at least iron, vitamin D, and zinc, I would say that's minimal nutrients that if you do in your bloodwork, you just order those. And then another thing that we advise is more than monitoring is just to prevention, right? So prevention of infections. So this is what we recommend every time we meet with the patients is, okay, are you updating your flu shot? Because we know that there is an increased risk of complications related to flu and celiac disease and there is an increased risk of infections including pneumonia. So we recommend pneumonia vaccination in celiac disease by guidelines.

Dr. Blair Bigham:

So, Ines, at some point the diagnosis is made and then it's off to a dietitian. Jadid, do you want to tell us where dietitians come into helping people get their celiac under control? Jedid-Jah Blom Yes. So the first thing is to understand what gluten is, right? It's a protein that's found in wheat, rye, and barley, but also in related grains because there are many different variants of wheat. And so things like spelt, kamut are also grains that contain gluten. And then the first step is to learn how to read food labels. So you need to know what the ingredients are that contain gluten. There's a long list that I have and we have those resources available on Celiac Canada's website as well. So a few examples of ingredients that you may not be aware of that contain gluten are, for example, dextrin or brewer's yeast, malt. So those you have to avoid. And so every time when the person goes shopping, they have to read the food labels of all the packaged foods that they're going to be purchasing. So it takes extra time to plan your shopping trip. They also need to avoid any foods that, say, may contain or contain wheat, rye, barley, gluten, or oats. And we have a short list of gluten-free oat products that we do recommend because not all the gluten-free oats are very transparent in how they're processing their oats. And also any foods that contain cornmeal or corn flour as the first or second ingredient, those are foods that we also need to be worried about because they are likely contaminated as well.

Dr. Mojola Omole:

Oh, wow. I didn't know that. Jedid-Jah Blom And then the second step is to learn to avoid gluten cross-contamination. So once you have selected your gluten-free ingredients or foods, then you need to make sure that during the storage, the food preparation, and the service that you're not contaminating the food with wheat flour or breadcrumbs or any flour dust that has gluten in it. So for example, you need to have your own gluten-free condiments. If you're using peanut butter in the family household, someone puts it on their wheat bread and puts the knife back into the peanut butter now that peanut butter has gluten in it. So it cannot be used by a person with celiac disease. Another step is to learn how to dine out. So this is the toughest part of following the gluten-free diet. For example, if you're ordering french fries, those fries need to be prepared in oil that's not contaminated with gluten because sometimes french fries can have coating on them that contains wheat or maybe they put some other breaded foods into the same fryer so then there are breadcrumbs left in the oil. Also things to check for are marinades, seasoning mixes, dressings. All of the ingredients need to be read. So you need to ask a lot of questions when you plan to eat out. Usually I tell my patients to use a certain app where they can read reviews of other people who have gone to eat out gluten-free to find a more suitable place and then they can send them an email or give them a phone call in advance to ask what options they have and how they're making sure that they're offering gluten-free food. So based on their response, usually you can get an idea of how well you can trust that place. And then the last step that's very important also is to make sure that the gluten-free diet that you're following is of good quality. What do you mean by good quality? We want people to follow Canada's food guide, but then in terms of the grains, we need to make sure that they're mostly whole gluten-free grains. For example, quinoa, amaranth, millet, sorghum, buckwheat. Those are examples of more whole grains, the gluten-free oats that we have on our list. Those are good options to make sure that you're getting enough fibre and enough of these nutrients that are in the whole grain. Because unfortunately, if you go with, for example, gluten-free flour mixes, those are not mandated to be fortified with iron, with folate and B vitamins. So you can't even develop deficiencies for those minerals and vitamins if you're choosing highly processed gluten-free foods. And usually those foods also have a higher sugar, fat, salt content to compensate for the texture difference and the flavouring of the food. So it's important to go by eating the least processed food as possible on the gluten-free diet. This seems like really, if someone got a diagnosis of it, that it could be quite overwhelming for them in terms of managing their diet. Can you walk me through how you help patients process and go through this? Jedid-Jah Blom Yes. So it might take multiple dietitian visits and checking in with the patient to see where they're at and always asking, acknowledging that it's very difficult to obtain all of this at once. We don't expect that from the patient either. So we keep checking in with them and asking them how we can best support them. And having different tools available for them. So we made a restaurant card, for example, that the patient can show to the staff at the restaurant where it says, I have celiac disease. I have to follow a gluten-free diet. I get symptoms if I get exposed to gluten. And so it gives them directions on how to select gluten-free foods and how to avoid cross-contamination. So that way they have one extra resource that they can show that this is not a diet by choice. This is a diet for managing their disease. It's the only treatment that we have available right now.

Dr. Maria Ines Pinto-Sáanchez:

One of the things that I want to mention is that it is very patient. Sometimes it depends on the patient. So there are patients that are in denial at the beginning and says, no, I cannot do this. I cannot do this gluten-free. I've been eating this in a different way for years. This is not possible that I have celiac disease. Can you check again the diagnosis? And then those patients take a long time to get them towards a gluten-free diet. So we cannot start talking about contamination when the patient is in denial of diagnosis.

Dr. Blair Bigham:

I can understand why people take it so seriously because it's so debilitating. But if you do have a perfect diet, if you never have a milligram of gluten, will you live symptom-free? Can anything else affect celiac presentation?

Dr. Maria Ines Pinto-Sáanchez:

I wish I could say yes, but that's not the case. So symptoms do not correlate with celiac disease activity. So someone can have a significant celiac very active and no symptoms at all. And some others may have a lot of symptoms and the celiac is not as much active. And in fact, the celiac can be remission and patients can still have symptoms. So there is an entity that is called non-responsive celiac, and that's based on persistent symptoms, despite people are trying to do and attempted to do a gluten-free diet very strictly. So unfortunately, we cannot correlate symptoms with disease activity. What we can say is that in the majority of celiac, 99% of celiac, if they do the diet perfect, as you said, then the celiac will be under good control and remission.

Dr. Blair Bigham:

We have covered a lot in the last 30 minutes, and your article is a beautiful review of all of this. If you wanted to summarize it with a quick takeaway for physicians, Jedid, let's start with you. What is the number one thing to have top of mind? Jedid-Jah Blom I think early referral to a dietitian is very important to make sure that they're getting the right information and that they don't have to do their own searching on the internet and how do I follow this diet and to understand better and feel more supported. Another referral that I think is important is to a psychologist to see how the patient is standing with their diagnosis and if they need further supports socially, emotionally, to be following this new lifestyle. And Ines, last word to you. What do people need to keep top of mind?

Dr. Maria Ines Pinto-Sáanchez:

I think celiac is quite common, and we should be more aware about celiac for early diagnosis, but also for proper diagnosis. Please don't put your patient on gluten-free until we have a proper diagnosis of celiac, and TTG alone is not enough to diagnose celiac. So, please, early and accurate diagnosis for celiac based on TTG and biopsies at the moment.

Dr. Blair Bigham:

Thank you so much for joining us. That was really informative.

Dr. Maria Ines Pinto-Sáanchez:

Thank you very much, Blair and Jola. Thank you very much.

Dr. Blair Bigham:

Jadid-Jah Blom and Dr. Maria Ines Pinto Sanchez are with the Celiac Disease Clinic and Farncombe Family Digestive Health Research Institute at McMaster University. So, Jola, I learned a lot in that segment. This is really, really interesting. I don't think I've ever tested for this as an emergency doctor, but certainly chronic GI symptoms are something we see far too often. And often, patients are just exasperated.

Dr. Mojola Omole:

For me, what was actually more interesting, because I do see chronic GI symptoms, it was more of the two parts of the fact that this could come on later on. You could have been negative four years ago, and it could be positive now. So, even someone who has IBS symptoms, I, for example, have IBS symptoms for most of my life. And so, I'm just like, yeah, it's just IBS, nothing else to worry about. But it was interesting to ponder the fact that for some people, they can, I guess, seroconversion, post-viral or something else, and also just keeping a broad differential to the fatigue, the brain fog, and a lot of this vague symptoms that people can have without GI symptoms that could still be celiac and needs to be ruled out with blood work.

Dr. Blair Bigham:

I'm also super interested in these extra-abdominal manifestations. Really fascinating. And also, they sound like they're maybe even more debilitating than some of the GI stuff.

Dr. Mojola Omole:

I think the GI stuff is bad, too. I think they're all debilitating. I'm sure it's all bad, yeah. People are just generally miserable, and once you know the answer, that is helpful. But definitely maintaining a gluten-free diet versus someone who's gluten-sensitive is very tricky. And also learning the fact that some of the gluten-free products, especially processed things, are not necessarily nutritionally dense. That is also something that I'm taking away to advise my patients about.

Dr. Blair Bigham:

That's a great point. So not only testing often for TTG when people have symptoms, in case it's negative that first time, keeping it high on your differential, but also, if you do get to that diagnosis, I guess preferentially from a biopsy, remembering that this diet is really going to change your life.

Dr. Mojola Omole:

For the good, but it is challenging.

Dr. Blair Bigham:

That's it for this episode of the CMAJ Podcast. The link to the study is in the show notes, and please follow or subscribe wherever you get your audio. If you can share, rate, or review our podcast, it helps others find it, and it helps us get the message out. The podcast is produced for CMAJ by Neil Morrison at Podcraft Productions. Catherine Varner is our Deputy Editor of CMAJ and Senior Editor on the podcast. I'm Blair Bigham.

Dr. Mojola Omole:

I'm Mojola Omole. Until next time, be well.