Are you confused about IBS and coeliac disease? Maybe you feel better without gluten in your diet, but you’re not sure whether you’ve been tested for coeliac disease or not.

The cross over between IBS and coeliac disease

1 in 4 people are misdiagnosed with IBS when they actually have coeliac disease. In this comparison study looking at the typical treatments for IBS, 28% of coeliac patients were given IBS advice, compared to 9% of controls.

Coeliac disease is an autoimmune condition which must be treated by a gluten free diet but the symptoms can be similar to IBS.

White persons hand holding a plate of white bread and white rolls. Blurred in the background a woman putting her hands up as it to say No to the bread.

How common is coeliac disease?

Around 1 in 10 people will have IBS in the UK, so it’s statistically more likely that someone would have IBS. But it’s thought around 1% of the UK adult population has undiagnosed coeliac disease.

That adds up to a lot of people in pain, with terrible symptoms for years and years. In fact, it can take 13 years on average to get diagnosed.

What is coeliac disease

Coeliac disease is a lifelong immune condition affecting the small intestine. If you have it, and you eat gluten it can lead to digestive symptoms like bloating, abdominal pain, gas and diarrhoea. Exposure to gluten can also lead to systemic whole body symptoms such as brain fog, nutrient deficiencies and fatigue.

If you’ve got coeliac disease and eat gluten your gut cells can attack themselves. Over time this can cause permanent damage to the lining of the gut.

Coeliac disease is not an allergy to gluten, although the immune system is involved.

Issues with untreated coeliac disease

People with coeliac disease must be super strict about gluten contamination. Even ingesting a tiny amount can affect sufferers.

If you imagine a million red marbles, and only 20 of these are blue, it’s a tiny proportion, right. But this is the size of the portion of gluten that can have in the gut of people with coeliac disease. Just 20 parts per million can trigger lasting damage to the gut lining.

That’s like 20 mg of gluten per kg of food. It’s not much at all, which is why people with coeliac disease need to be so strict about contamination.

Managing coeliac disease

Ideally there will be no gluten in the house, but if you live with other people who eat gluten you need to keep your things separate. People with coeliac disease need to have separate butter, jams and spreads so there are no crumbs in their food.

Kitchen drawers should be kept very clean to avoid any crumbs getting cutlery and cooking equipment. And when you’re eating out you need to ensure the restuarant understands how to keep gluten free foods separate. For more support check out Coeliac UK 

Damage to the gut villi

Gluten damage stops key nutrients being absorbed because the tiny villi in the gut lining can become shortened. This can lead to deficiencies in iron, protein, B vitamins and fat soluble nutrients.

When deficiencies become severe they may result in anaemia, joint pain and severe fatigue.

How would you know if you have coeliac disease?

Symptoms of coeliac disease are very similar to IBS, including bloating, abdominal pain, loose stools.

You cannot diagnose coeliac disease by looking at someone or guessing. You need to have a blood test to look for antibodies, and possibly a biopsy.

Important information about getting your coeliac disease test

NICE guidelines state an IBS diagnosis should include ruling out coeliac disease. This is because the symptoms are so similar. The problem is not everyone goes to their doctor about IBS, or they aren’t eating gluten before the blood test.

Testing for coeliac disease only works if you’ve been eating gluten daily for 6 weeks prior to the test. If you don’t eat gluten in the run up to the test, you may not have enough antibodies to show up in the blood. This could lead to a false negative result.

Don’t give up gluten before you’ve had a coeliac disease test

Before you trial a gluten free diet for IBS it’s worth getting a blood test to check for antibodies.

Is there another way to test for coeliac disease?

Maybe you’ve already trialled a gluten free diet, and feel worried about eating bread and pasta again daily. You might be concerned the symptoms will come back, and it’s not worth the risk.

There is a test to look for the genes which all people with coeliac disease have.

Genetic testing for coeliac disease

People with coeliac disease will have one or more copy of the following genes:

  • HLA DQ 2.5
  • HLA DQ8
  • HLA DQ2.2 

If you have the genes it doesn’t mean you have coeliac disease, but you won’t have coeliac disease if you don’t have the genes. Actually around 40% of the population might carry these genes and be ok. 


A selection of breads and brown uncooked spaghetti in a bundle. A small piece of cardboard with Gluten free written in black capitol letters..

I recommend everyone with IBS ask their GP to be tested for celiac disease as part of the process of diagnosing IBS, in line with the NICE guidelines.

Don’t give up gluten until you’ve already had this test or it won’t be valid.

For more information

If you’re struggling with IBS alongside coeliac disease then please get in touch about working with me in the 3 month Gut Reset. 

IBS Nutritionist

Hi, I'm Anna Mapson, registered Nutritional Therapist.

I help people with IBS and SIBO get control of unpredictable gut symptoms to find long term relief from painful and embarrassing IBS without restrictive dieting.

I can help you to:

  • understand your digestion better, so you recognise your triggers
  • eat a well balanced diet, with tasty meals that are simple to prepare
  • reintroduce your trigger foods so you can get back to enjoying food again

Find more about my 3 month 1:1 Gut Reset programme. 

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