Coeliac disease

Coeliac disease is a condition where your immune system attacks your own tissues when you eat gluten. This damages your gut (small intestine) so your body cannot properly take in nutrients.

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

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.

Symptoms of coeliac disease

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.

What causes coeliac disease?

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.

Treating coeliac disease

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 of coeliac disease

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.

Find out more about the complications of coeliac disease.

Who's affected

Coeliac disease is a condition that affects at least 1 in every 100 people in the UK.

But some experts think this may be underestimated because milder cases may go undiagnosed or be misdiagnosed as other digestive conditions, such as irritable bowel syndrome (IBS).

Reported cases of coeliac disease are higher in women than men.

It can develop at any age.

People with certain conditions, including type 1 diabetes, autoimmune thyroid disease, Down's syndrome and Turner syndrome, have an increased risk of getting coeliac disease.

First-degree relatives (parents, brothers, sisters and children) of people with coeliac disease are also at increased risk of developing the condition.

Diagnosing coeliac disease

Routine testing for coeliac disease is not done in England.

Testing is usually only recommended for people who have symptoms, or who have an increased risk of developing coeliac disease, such as those with a family history of the condition.

First-degree relatives of people with coeliac disease should be tested.

Read about diagnosing coeliac disease for more information about when testing for coeliac disease should be done.

 Symptoms Coeliac disease 

Symptoms of coeliac disease can range from mild to severe, and often come and go.

Mild cases may not cause any noticeable symptoms and the condition is often only detected during testing for another condition.

Treatment is recommended even when symptoms are mild or non-existent, because complications can still occur.

Common symptoms

Diarrhoea is a common symptom of coeliac disease. It's caused by the small bowel (intestines) not being able to absorb nutrients (malabsorption).

Malabsorption can also lead to stools (poo) containing abnormally high levels of fat (steatorrhoea). This can make them foul smelling, greasy and frothy. They may also be difficult to flush down the toilet.

Other common gut-related symptoms include:

• abdominal pain (stomach ache)
• bloating and flatulence (farting)
• indigestion
• constipation
• vomiting

And more general symptoms may include: 

• fatigue (extreme tiredness), which may be a sign of iron deficiency anaemia or vitamin B12 or folate deficiency anaemia
• unexpected weight loss
• an itchy rash (dermatitis herpetiformis)
• difficulty getting pregnant (infertility)
• tingling and numbness in your hands and feet (peripheral neuropathy)
• problems with co-ordination, balance and speech (ataxia)

Malnutrition

If coeliac disease is not treated, not being able to digest food in the normal way could cause you to become malnourished, leading to tiredness and a lack of energy.

Malnutrition in children can result in failure to grow at the expected rate, both in terms of height and weight. Children may also have delayed puberty.

Dermatitis herpetiformis

Although not a symptom of coeliac disease, if you have an autoimmune response to gluten, you may develop a rash called dermatitis herpetiformis.

The rash is itchy and has blisters that burst when scratched. It usually happens on your elbows, knees and buttocks, although it can appear anywhere on your body.

It's estimated that around 1 in 4 people with coeliac disease develop dermatitis herpetiformis.

The exact cause of dermatitis herpetiformis is not known, but as with coeliac disease, it's associated with eating gluten. Like coeliac disease, the rash should clear up after changing to a gluten-free diet.

 Causes Coeliac disease 

Coeliac disease is caused by an abnormal immune system reaction to the protein gluten, which is found in foods such as bread, pasta, cereals and biscuits.

It's an autoimmune condition, where the immune system mistakes healthy cells and substances for harmful ones and produces antibodies against them (antibodies usually fight off bacteria and viruses).

In the case of coeliac disease, your immune system mistakes one of the substances that makes up gluten, called gliadin, as a threat to the body. The antibodies that are produced cause the surface of your intestine to become inflamed (red and swollen).

The surface of the intestine is usually covered with millions of tiny tube-shaped growths called villi. Villi increase the surface area of your gut and help it to digest food more effectively.

However, in coeliac disease, the damage and inflammation to the lining of the gut flattens the villi, reducing their ability to help with digestion.

As a result, your intestine is not able to digest the nutrients from your food, which causes the symptoms of coeliac disease.

Oats

Some people with coeliac disease may find that eating oats can trigger symptoms. This is because some oats may be contaminated by other grains during production.

Oats also contain a protein called avenin, which is similar to gluten. Most people with coeliac disease can safely eat avenin. However, there's some evidence to suggest a very small number of people may still be sensitive to products that are gluten-free and do not contain contaminated oats.

Increased risk

It's not known why people develop coeliac disease. It's also not clear why some people have mild symptoms while others have severe symptoms.

However, several factors are known to increase your risk of developing coeliac disease.

Family history

Coeliac disease often runs in families. If you have a close relative with the condition, such as a parent, brother or sister, your chance of also getting it is increased.

This risk is approximately 10% for those with a family history. If you have an identical twin with coeliac disease, there's around a 75% chance you'll also develop the condition.

Research shows that coeliac disease is strongly associated with abnormal changes to the instructions that control cell activity (genetic mutations). These mutations affect the HLA-DQ genes, which are a group of genes responsible for the development of the immune system and may be passed down through a family.

However, mutations in HLA-DQ genes are very common. This suggests that something else, such as environmental factors, must trigger coeliac disease in certain people.

Environmental factors

You're more likely to develop coeliac disease if you had a digestive system infection (such as a rotavirus infection) during early childhood.

Most experts recommend waiting until your child is at least 6 months old before giving them food containing gluten.

There might also be an increased chance of babies developing coeliac disease if they're not being breastfed when gluten is introduced into their diet.

Find out more about your baby's first solid foods.

Other health conditions

Other health conditions can increase your risk of developing coeliac disease, including:

• type 1 diabetes
• thyroid conditions
• Down's syndrome 
• Turner syndrome

It's unclear whether these health conditions directly increase the risk of developing coeliac disease, or whether they and coeliac disease both have another, single underlying cause.

 Diagnosis Coeliac disease 

You should be tested for coeliac disease if you have any 1 of these symptoms:

• persistent unexplained gastrointestinal symptoms, such as diarrhoea, stomach ache and bloating
• faltering growth
• prolonged tiredness all the time (fatigue)
• unintentional weight loss
• severe or persistent mouth ulcers
• unexplained iron deficiency anaemia, or vitamin B12 or folate deficiency anaemia
• type 1 diabetes
• autoimmune thyroid disease, including an underactive thyroid (hypothyroidism) or overactive thyroid (hyperthyroidism)
• irritable bowel syndrome (IBS) (in adults)

Testing is also recommended if you have a first-degree relative (parent, sibling or child) with coeliac disease.

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 will 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.

Local groups

Many people feel overwhelmed when they're first diagnosed with coeliac disease. Switching to a gluten-free diet can be confusing, particularly if you've 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 following a gluten-free diet from your local coeliac disease support group.

 Treatment Coeliac disease 

Coeliac disease is treated by excluding foods that contain gluten from your diet.

This prevents damage to the lining of your intestines and the associated symptoms, such as diarrhoea and stomach pain.

If you have coeliac disease, you must stop eating all sources of gluten for life. Your symptoms will return if you eat foods containing gluten, and it will cause long-term damage to your health.

This may sound difficult to do, but a GP can give you help and advice about ways to manage your diet. Your symptoms should improve considerably within weeks of starting a gluten-free diet. However, it may take up to a few years for your digestive system to heal completely.

A GP will offer you an annual review during which your height and weight will be measured and your symptoms reviewed. They'll also ask you about your diet and assess whether you need any further help or specialist nutritional advice.

A gluten-free diet

When you're first diagnosed with coeliac disease, you'll be referred to a dietitian to help you adjust to your new diet without gluten. They can also ensure your diet is balanced and contains all the nutrients you need.

If you have coeliac disease, you'll no longer be able to eat foods that contain any barley, rye or wheat, including farina, semolina, durum, bulgar, cous cous and spelt.

Even if you only eat a small amount of gluten, such as a spoonful of pasta, you may have very unpleasant intestinal symptoms. If you keep eating gluten regularly, you'll also be at greater risk of developing complications, such as osteoporosis and some types of cancer in later life.

Find out more about the complications of coeliac disease.

Gluten is not essential in your diet and it can be replaced by other foods. There are many gluten-free versions of common foods such as pasta, pizza bases and bread available in supermarkets and health food shops. Some GPs may provide bread and flour mixes on prescription.

Many foods, such as meat, vegetables, cheese, potatoes and rice, are naturally free from gluten so you can still include them in your diet. A dietitian can help you identify which foods are safe to eat and which are not. If you're unsure, you can use the following lists as a general guide.

Foods containing gluten (not safe to eat)

If you have coeliac disease, do not eat the following foods, unless they're labelled as gluten-free versions:

• bread
• pasta
• cereals
• biscuits or crackers
• cakes and pastries
• pies
• gravies and sauces

It's important to always check the labels on the foods you buy. Many foods (particularly processed foods) include additives which contain gluten, such as malt flavouring and modified food starch.

Gluten may also be found in some non-food products, including some medicines.

Cross-contamination can happen if gluten-free foods and foods that contain gluten are prepared together or served with the same utensils.

Gluten-free foods (safe to eat)

If you have coeliac disease, you can eat the following foods, which naturally do not contain gluten:

• most dairy products, such as cheese, butter and milk
• fruits and vegetables
• meat and fish (although not breaded or battered)
• potatoes
• rice and rice noodles
• gluten-free flours, including rice, corn, soy and potato flour

By law, food labelled as gluten-free can contain no more than 20 parts per million (ppm) of gluten.

For most people with coeliac disease, these trace amounts of gluten will not cause a problem.

Oats

Oats do not contain gluten, but many people with coeliac disease avoid eating them because they can become contaminated with other cereals that contain gluten.

There's also some evidence to suggest that a very small number of people may still be sensitive to products that are gluten-free and do not contain contaminated oats. This is because oats contain a protein called avenin, which is suitable for most people with coeliac disease but may trigger symptoms in a few people.

If, after discussing this with your healthcare professional, you want to include oats in your diet, check the oats are pure and that there's no possibility of contamination with gluten. Avoid oats or oat products that are not labelled gluten-free.

Advice on feeding your baby

Do not introduce gluten into your baby's diet before they're 6 months old. Breast milk is naturally gluten-free as are all infant milk formulas.

Other treatments

As well as eliminating foods that contain gluten from your diet, there are other treatments available for coeliac disease.

Vaccinations

In some people, coeliac disease can cause the spleen to work less effectively, making you more vulnerable to infection.

You may therefore need to have extra vaccinations, including:

• flu vaccine
• Hib/MenC vaccine, which protects against sepsis (blood poisoning), pneumonia and meningitis (an infection of the lining of the brain)
• pneumococcal vaccine, which protects against infections caused by the Streptococcus pneumoniae bacterium

However, if your spleen is unaffected by coeliac disease, these vaccinations are not usually necessary.

Supplements

As well as cutting gluten out of your diet, a GP or dietitian may also recommend taking vitamin and mineral supplements if you need them, for example for iron deficiency anaemia.

This will ensure you get all the nutrients you need while your digestive system repairs itself.

Dermatitis herpetiformis

If you have dermatitis herpetiformis (an itchy rash that can be caused by gluten intolerance), cutting gluten out of your diet should help.

However, it can sometimes take longer for a gluten-free diet to clear the rash than it does to control your other symptoms, such as diarrhoea and stomach pain.

If this is the case, you may be prescribed medicine to speed up the healing of the rash. It's likely that this will be a medicine called dapsone, which usually comes as a tablet you swallow twice a day.

Dapsone can cause side effects, such as anaemia, headaches and depression, so you'll always be prescribed the lowest effective dose. You may have regular blood tests to check for anaemia.

You may need to take medicine for up to 2 years to control dermatitis herpetiformis. After this time, you should have been following a gluten-free diet long enough for the rash to be controlled without the need for medicine.

Refractory coeliac disease

Refractory coeliac disease is a rarer type of coeliac disease where the symptoms continue, even after switching to a gluten-free diet. The reasons for this are unclear.

If refractory coeliac disease is suspected, it's likely you'll be referred for a series of tests to make sure your symptoms are not being caused by another condition.

If no other cause can be found and the diagnosis is confirmed, you'll be referred to a specialist. Treatment options include steroid medicine, such as prednisolone, or immunosuppressant medicine, which help block the harmful effects of the immune system.

 Complications Coeliac disease 

If you have coeliac disease, it's crucial you do not eat any gluten. If you have untreated or undiagnosed coeliac disease and you're still eating gluten, several complications can occur.

It's a common misconception that eating a little gluten will not harm you. Eating even tiny amounts can trigger symptoms of coeliac disease and increase your risk of developing complications.

Malabsorption

Malabsorption (where your body does not fully absorb nutrients) can lead to a deficiency of vitamins and minerals. This can cause conditions such as:

• iron deficiency anaemia
• vitamin B12 or folate deficiency anaemia
• osteoporosis – a condition where your bones become brittle and weak

Malnutrition

As coeliac disease causes your digestive system to work less effectively, severe cases can sometimes lead to a critical lack of nutrients in your body. This is known as malnutrition, and can result in your body being unable to function normally or recover from wounds and infections.

If you have severe malnutrition, you may become fatigued, dizzy and confused. In children, malnutrition can cause stunted growth and delayed development.

Treatment for malnutrition can involve increasing the number of calories in your diet and taking supplements.

Find out more about treating malnutrition.

Lactose intolerance

If you have untreated coeliac disease, you're more likely to also develop lactose intolerance, where your body lacks the enzyme needed to digest the natural sugar (lactose) found in dairy products. Lactose intolerance causes symptoms such as bloating, diarrhoea and abdominal discomfort.

Unlike gluten in coeliac disease, lactose does not damage your body. But you may get some gut-related symptoms when you eat foods containing lactose because you can't digest it properly.

Lactose intolerance usually gets better once you change to a gluten-free diet and your gut has recovered. Until it gets better, it can be effectively treated by not eating or drinking dairy products that contain lactose. You may also need to take calcium supplements – dairy products are an important source of calcium, so you'll need to compensate for not eating them.

Cancer

Cancer is a very rare but serious complication of coeliac disease.

Someone with coeliac disease has a slightly increased risk of developing certain cancers. Recent research shows that this increased risk is less than previously thought.

Cancers associated with coeliac disease include small bowel cancer, small bowel lymphoma and Hodgkin lymphoma. However, most people with coeliac disease will not develop any of these.

Once you've been following a gluten-free diet for some time, your risk of developing these types of cancer is the same as that of the general population.

Coeliac disease in pregnancy

Poorly controlled coeliac disease in pregnancy can increase the risk of developing pregnancy-related complications, such as giving birth to a baby with a low birth weight.

You can also read more about a healthy diet in pregnancy.