How to get diagnosed

There are three steps in the diagnosis of adults with coeliac diseaseA condition where a person is unable to eat gluten as it makes their body attack itself. :

1. Discuss your symptoms with your GPGeneral Practitioner, or local doctor.
2. Get a simple blood testBlood is taken from someone who is being tested for coeliac disease. in your GP’s surgery. 
3. Get a referral to a gastroenterologistA doctor who specialises in the digestive system. for a gut biopsyThis simple procedure looks for gut damage. A thin tube is passed through the mouth, down to the upper part of the small intestine. Then a tiny sample of gut lining is collected. This can be done using local anaesthetic and/or sedation. .

For children a biopsy may not be necessary in every case. New guidelines have been published this year by BSPGHANBritish Society of Paediatric Gastroenterology, Hepatology and Nutrition - provides professional leadership, promotes standards of care for children with gastrointestinal, liver and nutritional diseases and supports research, training and education for members in order to help facilitate its delivery. and Coeliac UK recommending children with symptoms of coeliac disease whose blood tests show a high level of antibodiesExist in the blood and are used by the immune system to attack viruses or bacteria. and have the genes for coeliac disease may not need to have a biopsy to confirm the diagnosis. Your child’s GP can refer them to a paediatric gastroenterologist to make sure the correct tests are carried out.

Blood tests for coeliac disease

There are specific blood tests used to diagnosis coeliac disease. They look for antibodies that the body makes in response to eating glutenA protein that is found in the cereals wheat, barley and rye. .

The most accurate blood tests for coeliac disease are:

Tissue transglutaminase antibody (shortened to 'tTGA')
Endomysial antibody (shortened to 'EMAEndomysial antibody - an antibody that is measured in the blood as part of the diagnosis process for coeliac disease. Depending on the laboratory performing the test, one or more antibodies may be measured (see Tissue Transglutaminase)')

In adults, the test used depends on the laboratory performing the test - they may measure one of the antibodies, or sometimes both.

In children, the tTGA test is used and also a test to check for IgA deficiency. Further testing and investigations depend on the results. 

IgA deficiency

Some people with coeliac disease do not make the usual coeliac disease antibodies. This is called IgA deficiency and so your GP will need to test you differently for the condition.  If you have ongoing symptoms that suggest coeliac disease but you have had a negative blood test, then ask your GP to test you for IgA deficiency. NICENational Institute for Health and Clinical Excellence - an independent organisation responsible for providing national guidance on promoting good health and preventing and treating ill health. NICE had produced a clinical guideline on the recognition and assessment of coeliac disease. have a national guideline on recognition of coeliac disease and recommend that IgG EMA tests should be used in cases of confirmed IgA deficiency.

Genetic testing

More than 90% of people with coeliac disease have  HLA DQ2 and HLA DQ8 genes compared to 30% of the general population.

Although genetic testing cannot be used to diagnose coeliac disease as the associated genes are also present in people without coeliac disease, there is a role for genetic testing in eliminating uncertainties around diagnosis.

In adults, genetic testing is not routinely carried out but may be used to rule out coeliac disease, as if you do not have the associated genes, you are unlikely to have coeliac disease.

In children, genetic testing is used in conjunction with the antibody tests for coeliac disease to help support the diagnosis.

Gut biopsy

A biopsy involves a small camera called an endoscope being passed via your mouth and stomach into the small bowel. In adults, an anaesthetic spray is used to numb your throat and a sedative may also be given by injection. Biopsies are collected and examined under a microscope to check for the typical damage to the lining of the small bowel in coeliac disease.

EndoscopyAn investigation that looks inside your gut. The endoscope is a thin flexible tube that you swallow. It has a light and a camera and is passed via the mouth and into the upper part of the gut that is affected in coeliac disease. with biopsy can be used in both adults and children, but may not always be necessary in children. In young children, the endoscopy is performed under a general anaesthetic. If you have any concerns about testing, the best thing to do is to talk with your healthcare team.

Home testing kits

Home testing kits are now available over the counter and online. The Charity welcomes any development which can help people get diagnosed. There are some important things to think about in using such a test and we would always recommend consulting a doctor whatever the result of the test. You can read more about other tests for coeliac disease on our website.