Coeliac disease

Symptoms

Coeliac disease can cause a range of symptoms, including diarrhoea, abdominal pain and bloating.

Eating foods that contain gluten can trigger a range of gut symptoms, such as:

• diarrhoea, which may smell particularly unpleasant
• stomach aches
• bloating and farting (flatulence)
• indigestion
• constipation

Coeliac disease can also cause more general symptoms, including:

• tiredness (fatigue) as a result of not getting enough nutrients from food (malnutrition)
• unintentional weight loss
• an itchy rash (dermatitis herpetiformis)
• problems getting pregnant (infertility)
• nerve damage (peripheral neuropathy)
• disorders that affect co-ordination, balance and speech (ataxia)

Children with coeliac disease may not grow at the expected rate and may have delayed puberty.

Causes

Coeliac disease is an autoimmune condition. This is where the immune system (the body's defence against infection) mistakenly attacks healthy tissue.

In coeliac disease, the immune system mistakes substances found inside gluten as a threat to the body and attacks them.

This damages the surface of the small bowel (intestines), disrupting the body's ability to take in nutrients from food.

It's not entirely clear what causes the immune system to act this way, but a combination of genetics and the environment appear to play a part.

Coeliac disease is caused by an adverse reaction to gluten, which is a dietary protein found in 3 types of cereal:

• wheat
• barley
• rye

Gluten is found in any food that contains those cereals, including:

• pasta
• cakes
• breakfast cereals
• most types of bread
• certain types of sauces
• some ready meals

In addition, most beers are made with barley.

Diagnosis

Testing for coeliac disease involves having a blood test. You may also need a biopsy of the small intestine, to confirm the diagnosis.

While being tested for coeliac disease, you'll need to eat foods containing gluten to ensure the tests are accurate. You should also not start a gluten-free diet until the diagnosis is confirmed by a specialist, even if the results of a blood test are positive.

Blood test

A GP may arrange a blood test to check for antibodies usually present in the blood of people with coeliac disease.

You should include gluten in your diet when the blood test is done because avoiding it could lead to an inaccurate result.

If coeliac disease antibodies are found in your blood, the GP will refer you to a doctor who specialises in stomach and bowel conditions (gastroenterologist). The specialist may arrange more blood tests, or a biopsy of your intestine.

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

If you continue to have symptoms of coeliac disease, despite having a negative blood test, the GP may still refer you to a specialist.

Biopsy

A biopsy is done in hospital, usually by a gastroenterologist. A biopsy can help confirm a diagnosis of coeliac disease.

A thin, flexible tube with a light and camera at one end (endoscope) will be inserted into your mouth and passed down to your small intestine.

Before the procedure, you'll be given a local anaesthetic to numb your throat and perhaps 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're diagnosed with coeliac disease, you may also have other tests to assess how the condition has affected you.

You may have more blood tests to check the levels of iron and other vitamins and minerals in your blood. This will help determine whether coeliac disease has caused problems such as iron deficiency anaemia (a lack of iron in your blood) from poor absorption of nutrients.

If you appear to have dermatitis herpetiformis (an itchy rash), you may have a skin biopsy to confirm it. This will be done under local anaesthetic and involves a small skin sample being taken so it can be examined under a microscope.

A DEXA scan may also be recommended if a GP thinks your condition may have affected your bones. This is because in coeliac disease, the poor absorption of nutrients can make bones weak and brittle (osteoporosis). A DEXA scan is a type of X-ray that measures bone density to see whether you're at risk of bone fractures as you get older.

Treatment Options

There's no cure for coeliac disease, but following a gluten-free diet should help control symptoms and prevent the long-term complications of the condition.

Even if you have mild symptoms, changing your diet is still recommended because continuing to eat gluten can lead to serious complications. This may also be the case if tests show that you have some degree of coeliac disease even if you do not have noticeable symptoms.

It's important to ensure that your gluten-free diet is healthy and balanced.

An increase in the range of available gluten-free foods in recent years has made it possible to eat both a healthy and varied gluten-free diet.

Complications

Complications of coeliac disease only tend to affect people who continue to eat gluten, or those who have not yet been diagnosed with the condition, which can be a common problem in milder cases.

Potential long-term complications include:

• weakening of the bones (osteoporosis)
• iron deficiency anaemia
• vitamin B12 or folate deficiency anaemia

Less common and more serious complications include some types of cancers, such as bowel cancer, and problems affecting pregnancy, such as your baby having a low birth weight.