Do I really have coeliac disease?

I keep seeing the same sort of post in coeliac disease groups on Facebook. It'll be a post about whether someone really has coeliac disease because they've been diagnosed on blood tests alone.

What tends to happen is lots of people jump on in the comments saying:

• you can't be diagnosed without a biopsy; and

• you can't be diagnosed by your GP - it has to be a specialist.

And while these points are usually valid, there are some exceptions.

So what's a proper coeliac disease diagnosis?

Firstly, things are beginning to change. Specialists in gut health are now debating rolling out a no-biopsy diagnosis and sometimes you'll get a diagnosis from blood tests alone. This can happen with patients who are very young (and then it's recommended they get re-tested when they're older) or in patients where the surrounding evidence makes it clear it's highly likely to be coeliac disease (and they've ruled out anything else).

What sort of evidence are they looking for?

There are a number of issues that might allow a patient to be diagnosed without a biopsy. These include:

• very high levels of antibodies in the blood tests

• a family history of coeliac disease

• strong symptoms concurrent with coeliac disease

• if you have another autoimmune condition (like type 1 diabetes)

(N.B. This isn't an exhaustive list.)

But the usual method of diagnosis for a coeliac is to have the biopsy (it's considered a definitive method of proving whether someone has coeliac disease). The specialist will look at the lining of the intestine to see if there's been any damage. It's not usually possible to detect without taking a small sample and then examining it under a microscope, which is why people often have to wait for a few weeks after their endoscopy to have a diagnosis.

But! There's one very important condition:

You must be eating gluten to get a positive test result.

When I was diagnosed with coeliac disease, the advice was to eat gluten for a week before the tests (both blood tests and biopsy). Although I was lucky enough to get a positive test from this, the advice nowadays is to eat enough gluten for six weeks at least twice a day (e.g. a slice of wheat bread or a bowl of wheat pasta at separate meals).

I realise how awful that sounds to anyone who's really suffering. It's like being told to eat poison! The way I got through it was this: I was excited to eat foods I hadn't been able to have for a while (I definitely went to Miss Millie's Cookies!) and then clenched my teeth every time I had the dreaded symptoms of pain in my tummy.

Times when you shouldn't diagnose coeliac disease on blood tests alone

The blood tests are considered 98% effective in adults and, in a recent webinar I attended at Harvard University, 88% effective in children. That means 2% of the time they give a false result in an adult and 12% of the time they give a false result in a child.

So if it's possible to do a biospy, it's really advisable so you get an accurate result. There are cases of people having false negatives and it's crucial you get an accurate diagnosis so they can rule out anything else.

But the specialists know so much more than your GP will, and that's why GPs make referrals to gastroenterologists who specialise in areas like your intestines and gut health in general. So if they're happy to diagnose based on just blood tests, it's likely they've made an accurate diagnosis.

Whatever happens, make sure you go over things thoroughly with your consultant so you're not left confused when you go home. If at all possible, take someone with you who can make notes on your behalf. It's easy to forget how much you won't be able to take in when you're undergoing a life-changing diagnosis. (And while we're here, although coeliac disease is life-changing, you can still live a fantastic and fulfilling life, so please don't panic. There is quite a bit to learn, though, so it may take time to get your head round all your new rules.)

I'd love to know if this blog post has helped you or if you have further questions. Let me know below!