Routine screening for coeliac disease is not recommended unless you have symptoms or are at an increased risk of developing them.

Screening for coeliac disease involves a two-stage process:

• blood tests – to help identify people who may have coeliac disease
• a biopsy – to confirm the diagnosis

These procedures are described in more detail below.

Blood test

Your GP will take a blood sample and test it for antibodies usually present in the bloodstream of people with coeliac disease.

You should not be avoiding gluten in your diet when the blood test is done as this could lead to an inaccurate result.

If coeliac disease antibodies are found in your blood, your GP will refer you for a biopsy of your gut.

However, it is sometimes possible to have coeliac disease and not have these antibodies in your blood.

If you continue to have coeliac disease-like symptoms despite having a negative blood test, your GP may still recommend you have a biopsy.

Biopsy

A biopsy is carried out in hospital, usually by a gastroenterologist (a specialist in treating conditions of the stomach and intestines). A biopsy can help confirm a diagnosis of coeliac disease.

If you need to have a biopsy, an endoscope (a thin, flexible tube with a light) will be inserted into your mouth and gently passed down to your small intestine.

Before the procedure, you will be given a local anaesthetic to numb your throat or a sedative to help you relax.

The gastroenterologist will pass a tiny biopsy tool through the endoscope to take samples of the lining of your small intestine. The sample will then be examined under a microscope for signs of coeliac disease.

Tests after diagnosis

If you are diagnosed with coeliac disease, you may also have other tests to assess how the condition has affected you so far.

You may have further blood tests to check levels of iron and other vitamins and minerals in your blood. This will help determine whether coeliac disease has led to you developing anaemia (a lack of iron in your blood) as the result of poor digestion.

If you appear to have dermatitis herpetiformis (an itchy rash caused by gluten intolerance), you may have a skin biopsy to confirm it.

This is carried out under local anaesthetic, where a small skin sample is taken from the area so it can be examined under a microscope.

In some cases of coeliac disease, a DEXA scan may also be recommended. A DEXA scan is a type of X-ray that measures bone density. It may be necessary if your GP thinks your condition may have started to thin your bones.

In coeliac disease, a lack of nutrients caused by poor digestion can make bones weak and brittle (osteoporosis). This is not a test for arthritis, and only looks at bone density to see if you are at risk of bone fractures as you get older.

Local groups

Many people feel overwhelmed when first diagnosed with coeliac disease. Switching to a gluten-free diet can be confusing, particularly if you have been eating foods that contain gluten for many years.

In the first few months after being diagnosed, many people accidentally eat foods that contain gluten, which may trigger a return of their symptoms.

You can learn more about coeliac disease and receive practical advice about switching to a gluten-free diet by contacting your local coeliac disease support group.

Groups support people with coeliac disease, including those recently diagnosed and those who have been living with the condition for years.

The Coeliac UK website provides further information as well as advice and details of support groups in your area.

NICE guidance

In 2009, the National Institute for Health and Care Excellence (NICE) issued guidance about when testing for coeliac disease should be carried out.

The guidance recommended testing for adults or children with the following signs or symptoms:

• long-term (chronic) diarrhoea or repeated and regular episodes of diarrhoea
• persistent or unexplained gastrointestinal symptoms, such as feeling sick and being sick
• fatigue (feeling tired all the time)
• recurring abdominal pain
• cramping or bloating
• sudden or unexplained weight loss
• unexplained anaemia  
• failure to thrive in infants and toddlers

Testing is also recommended if you have a close relative (parent, sibling or child) with coeliac disease or if you have the following conditions:

• type 1 diabetes 
• irritable bowel syndrome (IBS)
• underactive thyroid or overactive thyroid glands
• dermatitis herpetiformis (a skin condition that causes blistering)

In some circumstances, testing may also be recommended if you have any of the following conditions:

• Addison's disease – a condition where the immune system attacks certain glands in the body
• Down's syndrome – a genetic condition that causes abnormal physical and mental development
• epilepsy
• lymphoma – a type of cancer
• bone diseases, such as rickets – a condition that causes softening and weakening of the bones
• persistent or unexplained constipation
• repeated miscarriages
• Sjogren's syndrome – a condition where the immune system attacks the tear and saliva glands
• Turner syndrome – a genetic condition that only affects women and causes infertility and delayed growth
• unexplained infertility

Read the NICE guidelines on the recognition and assessment of coeliac disease.