How To Diagnose Coeliac

Let’s talk about your gut. Specifically, the mystery that is coeliac disease. It’s like your body decided to throw a tiny protest against a slice of toast. And that protest? It’s surprisingly dramatic.

Coeliac isn’t a food allergy. It’s an autoimmune party crasher. Your immune system sees gluten—a protein in wheat, barley, and rye—and declares war on you. It attacks the lining of your small intestine. The result? A mess of symptoms that look like everything else.

The Symptom Switcheroo

First, the classic symptoms. The “I ate bread and now I’m a human balloon” scenario. Bloating, gas, diarrhea, and tummy pain that feels like a tiny gremlin doing jumping jacks. But here’s the kicker: you can have zero of those.

Some people get constipation instead. Or mysterious fatigue. One friend of mine had crippling migraines for years. Her doctor said “stress.” It was actually coeliac. Your body can rebel in bizarre ways. We’re talking anemia, itchy skin rashes (called dermatitis herpetiformis—fancy, huh?), even joint pain.

Fun fact: The rash looks like blisters and burns like crazy. People have been told it’s “just eczema” for decades. Spoiler: it’s not.

The “Belly vs. Brain” Connection

Coeliac loves messing with your head. Brain fog, anxiety, and depression are common. You might feel like you’re running on dial-up internet. Your gut and brain are literally connected by the vagus nerve. When your gut is inflamed, your brain throws a tantrum.

There’s even a condition called “gluten ataxia.” It makes you lose balance and coordination. I’m not joking. One woman thought she had multiple sclerosis. She went gluten-free and started walking straight again. Mad science.

How Do You Actually Get Diagnosed?

Here’s the golden rule: Do not stop eating gluten before testing. If you go gluten-free, the damage heals, and the test lies. You need to be eating the equivalent of two slices of bread daily for at least six weeks. The “gluten challenge” is brutal. It feels like punishing your body on purpose. But it’s necessary.

Step one: see your doctor. Ask for a tTG-IgA blood test. That’s short for tissue transglutaminase antibodies. You want a huge number in the results. If your immune system is active, it shows up like a flare in the night.

Step two: if the blood test glows red, you need an endoscopy with a biopsy. Sounds scary, but you’re asleep. A camera goes down your throat, takes tiny samples of your small intestine. Pathologists look for flattened villi—the tiny finger-like soldiers that absorb nutrients. When they’re flattened, you have coeliac.

Quirky detail: Your villi are meant to look like shag carpet. With coeliac, they look like a bald tire. Scientists actually use the “Marsh score” to rank damage. Stage 0 is healthy. Stage 3 is “please stop eating bread immediately.”

The Tricky “Maybe” People

Some folks get a positive blood test but a negative biopsy. That’s called potential coeliac disease. Doctors will say, “We’re not sure.” Or “wait and see.” Classic medicine.

Others have seronegative coeliac. Their blood tests look perfect, but their gut is a war zone. These patients often get diagnosed only after years of misery. Or after a doctor gets curious and does an endoscopy anyway. Insist on the scope if your symptoms won’t quit.

And then there’s the genetic test. It looks for the HLA-DQ2 or HLA-DQ8 genes. Most people have these genes and never get coeliac. So a positive gene test doesn’t mean you have it. But a negative gene test? You’re off the hook. You can rule out coeliac forever. That’s a relief.

Why This Is Actually Fun

Okay, “fun” is a stretch. But the detective work is incredible. You’re looking for tiny clues your body is leaking. The rash, the brain fog, the weird bruising. Every symptom is a breadcrumb.

The diagnosis process is like a treasure hunt with your own organs. You get to annoy your doctor with questions. You get to feel like a medical sleuth. And when you finally get the answer—whether it’s coeliac or not—you can say, “I knew something was up.”

Plus, the gluten-free world is wild. There are pasta made from chickpeas, crackers from cassava, and bread that tastes like cardboard but somehow works. You become a label detective. You learn that “wheat-free” is not the same as “gluten-free.” You become a snob about soy sauce (it has wheat!).

And the best part? The community. Coeliacs are the most supportive people on the internet. They’ll share their favorite pizza crust recipe and warn you about cross-contamination at your local diner. They know the secret: it’s not about being gluten-free. It’s about feeling human again.

The Punchline

So how do you diagnose coeliac? You don’t guess. You test. See a gastroenterologist. Eat all the bread. Get the blood work. Get the camera. Demand the biopsy.

It’s a weird journey. You’ll talk about your poop more than you ever imagined. You’ll feel worse before you feel better. But once you know? You own your health. You take back control.

And the next time someone offers you a croissant? You’ll smile, say “no thanks, my immune system would fight a war for this,” and enjoy your dark chocolate instead. That’s the win.