Coeliac disease is a common digestive condition where a person has an adverse reaction to gluten.
Eating foods containing gluten can trigger a range of symptoms, such as:
diarrhoea, which may smell particularly unpleasant
bloating and flatulence (passing wind)
feeling tired all the time as a result of malnutrition (not getting enough nutrients from food)
children not growing at the expected rate
Symptoms can range from mild to severe.
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.
Coeliac disease isn't an allergy or an intolerance to gluten.
In cases of 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 absorb nutrients from food.
Exactly what causes the immune system to act in this way is still not entirely clear, although a combination of a person's genetic make-up and the environment appear to play a part.
Gluten is a protein found in three types of cereal:
Gluten is found in any food that contains the above cereals, including:
most types of bread
certain types of sauces
some types of ready meals
In addition, most beers are made from barley.
Treating coeliac disease
There is no cure for coeliac disease, but switching to a gluten-free diet should help control symptoms and prevent the long-term consequences of the disease.
Even if symptoms are mild or non-existent, it is still recommended to change your diet, as continuing to eat gluten can lead to serious complications.
It is important to make sure 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.
Currently, screening for coeliac disease is not routinely carried out in England.
It is usually only recommended for people at an increased risk of developing the condition, such as those with a family history of the disease.
It is recommended that first-degree relatives (parents, brothers, sisters and children) of people with coeliac disease are screened.
Complications of coeliac disease only tend to affect people who continue to eat gluten or who have yet to be diagnosed with the condition, which can be a common problem in milder cases.
Potential long-term complications include:
osteoporosis (weakening of the bones)
iron deficiency anaemia
vitamin B12 and folate deficiency anaemia
Less common and more serious complications include those affecting pregnancy, such as having a low-birth weight baby, and some types of cancers, such as bowel cancer.
Who is affected?
Coeliac disease is a common condition that affects approximately 1 in every 100 people in the UK.
However, some experts think this may be an underestimate 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 two to three times higher in women than men and can develop at any age, although symptoms are most likely to develop:
during early childhood – at between 8 and 12 months old (though it may take several years before a correct diagnosis is made)
in later adulthood – between the ages of 40 and 60 years
Gluten is a protein found in wheat, barley and rye
The UK's leading charity for people affected by coeliac disease is Coeliac UK.
Their website contains a range of useful resources, including information on gluten-free diets and specific products, as well as the details of local groups, volunteering and ongoing campaigns.
The charity also has a telephone helpline on 0845 305 2060, open Monday to Friday from 9am to 5pm.
Symptoms of coeliac disease
Symptoms of coeliac disease can range from mild to severe, and often come and go.
Mild cases of coeliac disease may not cause any noticeable symptoms, and the condition is often only detected during testing for another condition.
However, treatment is recommended as complications can still occur in these cases.
The most common symptom of coeliac disease is diarrhoea, caused by the body not being able to fully absorb nutrients (malabsorption).
Malabsorption can also lead to stools 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 symptoms include:
bloating or abdominal (stomach) pain
flatulence and a noisy stomach
tiredness and fatigue, which may be a sign of iron deficiency anaemia or folate deficiency anaemia
tingling and numbness in your hands and feet (peripheral neuropathy)
vomiting (usually only affects children)
swelling of your hands, feet, arms and legs caused by a build-up of fluid (oedema)
If coeliac disease is untreated, being unable to digest food in the normal way could cause you to become malnourished, making you feel tired and lacking in energy.
Malnutrition in children can lead to failure to grow at the expected rate, both in terms of weight and height, as well as delayed puberty in older children.
Although not a symptom of coeliac disease, if you have an autoimmune response to gluten, you may also develop a type of skin rash known as dermatitis herpetiformis.
The rash is itchy and characterised by blisters that burst when scratched. The rash usually appears on your elbows, knees and buttocks, although it can appear anywhere on your body.
It is estimated around one in five people with coeliac disease also develop dermatitis herpetiformis.
The exact cause of dermatitis herpetiformis is not known, but, as with coeliac disease, the condition is associated with gluten. Like coeliac disease, it should clear up after switching to a gluten-free diet.
Diarrhoea is the passing of watery stools more than is normal for you. It is often a symptom of an infection or long-term condition. In this video, Dr Rupal Shah explains the most common causes of diarrhoea and the effects it can have on your body.
Media last reviewed: 30/04/2013
Next review due: 30/04/2015
Is it a food allergy or intolerance?
Around 2% of people in the UK have a food allergy, but many more have a food intolerance
Causes of coeliac disease
Coeliac disease is caused by an abnormal reaction by your immune system to the protein gluten, found in foods such as bread, pasta, cereals and biscuits.
Some people with coeliac disease find eating oats can also trigger symptoms.
Coeliac disease is an example of an autoimmune condition, when your 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 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 your gut flattens the villi, which reduces their ability to help with digestion.
As a result, your intestine is no longer able to digest nutrients from your food, leading to the symptoms of coeliac disease.
It is not known exactly why people develop coeliac disease, or why some have mild symptoms while others have severe symptoms.
However, the below factors are known to increase your risk of developing coeliac disease.
Coeliac disease often runs in families. If you have a close relative with the condition, such as a parent or sibling, your chance of developing it is higher.
This risk is approximately 10% for those with a family history. If you have an identical twin with coeliac disease, there is a 75% chance you will also develop the condition.
Research shows coeliac disease is strongly associated with a number of genetic mutations (abnormal changes to the instructions that control cell activity) that affect a group of genes called the HLA-DQ genes. HLA-DQ genes are responsible for the development of the immune system and may be passed down through a family.
However, mutations in the HLA-DQ genes are common and occur in about one-third of the population. This suggests that something else, such as environmental factors, must trigger coeliac disease in certain people.
It is thought environmental factors, including an infection of the digestive system (such as a rotavirus infection) during early childhood, play a part in developing coeliac disease.
There is evidence introducing gluten into your baby's diet before they are three months old may increase their risk of developing coeliac disease.
Most experts recommend you wait until your child is at least six months old before giving them food containing gluten.
There might also be an increased chance of babies developing coeliac disease if they are not being breastfed when gluten is introduced into the diet.
Other health conditions
A number of other health conditions can increase your risk of developing coeliac disease. Health conditions associated with coeliac disease include:
type 1 diabetes
ulcerative colitis – a digestive condition that causes inflammation of the colon (large bowel)
neurological disorders (which affect the brain and nervous system) such as epilepsy
See diagnosing coeliac disease for a more extensive list of conditions associated with coeliac disease.
It is unclear whether these health conditions are independent risk factors for developing coeliac disease, or whether they and coeliac disease are both caused by another, single underlying cause.
Diagnosing coeliac disease
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.
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.
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.
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.
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
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
lymphoma – a type of cancer
bone diseases, such as rickets – a condition that causes softening and weakening of the bones
persistent or unexplained constipation
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
Treating coeliac disease
Coeliac disease is usually treated by simply excluding foods that contain gluten from your diet.
This prevents damage to the lining of your intestines (gut) and the associated symptoms, such as diarrhoea and stomach pain.
If you have coeliac disease, you must give up all sources of gluten for life because eating foods that contain it will cause your symptoms to return, as well as long-term damage to your health.
This may sound daunting, but your 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 two years for your digestive system to heal completely. You will also need to return to your GP for regular check-ups.
A gluten-free diet
When you are first diagnosed with coeliac disease, you will 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 will no longer be able to eat foods that contain barley, rye or wheat, including farina, graham flour, semolina, durum, cous cous and spelt.
Even if you only consume a small amount of gluten, such as a spoonful of pasta, you may have very unpleasant intestinal symptoms. If you keep consuming gluten regularly, you will also be at greater risk of osteoporosis and cancer in later life.
As a protein, gluten is not essential to your diet and can be replaced by other foods. Many gluten-free alternatives are widely available in supermarkets and health food shops, including pasta, pizza bases and bread. A range of gluten-free foods is also available on prescription.
Many basic foods – such as meat, vegetables, cheese, potatoes and rice – are naturally free from gluten so you can still include them in your diet. Your dietitian can help you identify which foods are safe to eat and which are not. If you are unsure, use the lists below as a general guide.
Foods containing gluten (unsafe to eat)
If you have coeliac disease, do not eat the following, unless they are labelled as gluten-free versions:
biscuits or crackers
cakes and pastries
gravies and sauces
It is important to always check the labels of the foods you buy. Many foods – particularly those that are processed – contain gluten in additives, such as malt flavouring and modified food starch.
Gluten may also be found in some non-food products, including lipstick, postage stamps and some types of medication.
Cross-contamination can occur 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
fruit and vegetables
meat and fish (although not breaded or battered)
gluten-free flours, including rice, corn, soy and potato
By law, food labelled as gluten free can contain no more than 20 parts per million (ppm) of gluten.
For most people, these trace amounts of gluten will not cause any problem. However, there are a minority of people with coeliac disease who are unable to tolerate even trace amounts of gluten and require a diet completely free from cereals.
The Coeliac UK website also contains information and advice about living with the condition, including a gluten-free diet and lifestyle.
Oats do not contain gluten, but many people with coeliac disease avoid eating them because they can become contaminated with other cereals that do contain gluten.
If, after discussing this with your health professional, you want to include oats in your diet, check the oats are pure and there is no possibility contamination could have occurred.
It is recommended you should avoid eating oats until your gluten-free diet has taken full effect and your symptoms have been resolved. Once you are symptom free, gradually reintroduce oats into your diet. If you develop symptoms again, stop eating oats.
Advice on feeding your baby
Do not introduce gluten into your baby's diet before they are six months old. Breast milk is naturally gluten free and all infant milk formulas are, too.
If you have coeliac disease, Coeliac UK recommends gluten-containing foods are introduced gradually when a child is six months old. This should be monitored carefully.
As well as eliminating foods that contain gluten from your diet, a number of other treatments are available for coeliac disease. These are described below.
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 (influenza) jab
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.
As well as cutting gluten out of your diet, your GP or dietitian may also recommend you take vitamin and mineral supplements, at least for the first six months after your diagnosis.
This will ensure you get all the nutrients you need while your digestive system repairs itself. Taking supplements can also help correct any deficiencies, such as anaemia (a lack of iron in the blood).
If you have dermatitis herpetiformis (an itchy rash that can be caused by gluten intolerance), cutting gluten out of your diet should clear it up.
However, sometimes it can 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 medication to speed up the healing time of the rash. It is likely this will be a medicine called Dapsone, which is usually taken orally (in tablet form) twice a day.
Dapsone can cause side effects, such as headaches and depression, so you will always be prescribed the lowest effective dose.
You may need to take medication for up to two years to control your 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 medication.
The Crossed Grain symbol – created by Coeliac UK and promoted by coeliac organisations worldwide – is a food labelling symbol that confirms that a labelled food product is gluten-free
Refractory coeliac disease
A rarer type of coeliac disease is refractory coeliac disease. In this form of the condition, for reasons that are still unclear, the symptoms continue to persist even when a person has switched to a gluten-free diet.
It is estimated around 1 in every 140 people with coeliac disease will develop the refractory form of the condition.
If you do develop suspected refractory coeliac disease, it is likely you will be referred for a series of tests to make sure your symptoms are not being caused by some other condition.
If no other cause can be found and the diagnosis is confirmed, you will likely be referred to a specialist. Treatment options include steroid medication (corticosteroids), which can help block the harmful effects of the immune system.
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Seven simple steps to make day-to-day living with a long-term health condition easier
Complications of coeliac disease
If you have coeliac disease, it is crucial you do not eat any gluten. If you have untreated or undiagnosed coeliac disease and are still eating gluten, several complications can occur.
It is 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 the complications outlined below.
Malabsorption (where your body does not fully absorb nutrients) can lead to a deficiency of certain vitamins and minerals. This can lead to certain conditions, including:
iron deficiency anaemia
vitamin B12 and folate deficiency anaemia
osteoporosis – this causes your bones to become brittle and weak
Click on the links above for more information on the symptoms and treatment of these conditions.
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 mean your body is unable to function normally or recover from wounds and infections.
If you have severe malnutrition, you may become fatigued, dizzy and confused. Your muscles may begin to waste away and you may find it difficult to keep warm. In children, malnutrition can cause stunted growth and delayed development.
Treatment for malnutrition usually involves increasing the number of calories in your diet and taking supplements.
If you have coeliac disease, you are more likely to also develop lactose intolerance, where your body lacks the enzyme to digest the milk sugar (lactose) found in dairy products. Lactose intolerance causes symptoms such as bloating, diarrhoea and abdominal discomfort.
Unlike gluten in coeliac disease, lactose intolerance does not damage your body. Rather, you may get some gastrointestinal symptoms when you take foods containing lactose as you can't digest it properly.
Lactose intolerance can be effectively treated by not eating and drinking dairy products that contain lactose. You may also need to take calcium supplements – as dairy products are an important source of calcium, you will need to compensate for not eating them.
Some research has suggested having coeliac disease can increase your risk of developing certain types of cancer, including bowel cancer and lymphoma (cancer of the lymphatic system, which is part of the immune system).
The same research found people with coeliac disease have a lower risk of developing lung and breast cancer, although the reasons for this are unclear.
It is estimated people with coeliac disease are twice as likely to develop bowel cancer than the general population.
However, this is still a very small increase in risk – only 1 in every 200 people with coeliac disease will develop bowel cancer in the first 10 years after diagnosis.
As age is an independent risk factor for bowel cancer, your risk of developing bowel cancer increases as you get older, in line with the general population.
The risk of developing cancer is thought to be highest during the first year after diagnosis, before dropping to normal as your gluten-free diet starts to take effect.
Whether or not you have coeliac disease, it is important to be aware of the symptoms of bowel cancer, which include:
blood in stools (faeces)
unexplained weight loss
changes in your normal bowel habit that last more than four weeks
See your GP if you develop these symptoms.
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 low birth weight baby.