Coeliac disease, also known as celiac disease, is a common digestive condition where a person is intolerant (has an adverse reaction) to the protein gluten. If someone with coeliac disease is exposed to gluten, they may experience a wide range of symptoms and adverse effects, including:
- abdominal pain
- weight loss
- failure to grow at the expected rate
The Coeliac Society of Ireland is the national charity organisation providing support and information for people living with coeliac disease. The Society produces an annual Food List booklet, a magazine and a monthly ezine, all available on joining. The Society has a website with information and advice on Coeliac Living, including a member’s forum, recipes and information on travelling and eating out.
Coeliac disease is an auto-immune disease, which means that the body's immune system attacks itself. When people with this condition eat gluten, this results in damage to the lining of the small intestine, which stops the body properly absorbing nutrients. The symptoms of coeliac disease can range from very mild to severe.
Gluten is a protein that is found in three types of cereal:
- Oats (only gluten-free Pure Oats are suitable for coeliacs and then only after the first year and with monitoring by health professionals, as up to 5% of coeliacs may not be able to tolerate even pure oats).
Gluten is also found in many processed foods and coeliacs should check labels as well as checking the Coeliac Society of Ireland’s annual Food List for foods suitable to use.
Gluten is found in any food that contains the above cereals including:
- breakfast cereals
- most type of bread
How common is coeliac disease?
During the 1980s, before advances in testing for coeliac disease were made, the condition was mistakenly thought to be rare.
However, coeliac disease is now known to be a common condition that affects approximately 1 in every 100 people. Women are two to three times more likely to develop coeliac disease than men. Cases of coeliac disease have been diagnosed in people of all ages.
In some cases, coeliac disease does not cause any noticeable symptoms, or it causes very mild symptoms. As a result, it is thought that at least 50% or possibly as many as 90% of cases are either undiagnosed or misdiagnosed as other digestive conditions, such as irritable bowel syndrome (IBS).
The cause or causes of coeliac disease are unknown, but it is thought to be associated with a combination of genetic and environmental factors.
If successfully diagnosed, the outlook for coeliac disease is generally good. There is no cure for coeliac disease, but switching to a gluten-free diet should help control the condition's symptoms.
The outlook for untreated coeliac disease can range from moderate to poor. Without treatment, coeliac disease can cause a wide range of potential long-term complications such as:
- osteoporosis (weakening of the bones)
- growth defects
- some types of cancer
Currently, screening for coeliac disease is not routinely carried out. The tests for coeliac disease are reasonably, but not completely, accurate. This means that routinely screening the entire population could produce a high number of false-positive results. In other words, people would be misdiagnosed as having coeliac disease when they did not have it.
Therefore, screening for coeliac disease is usually only recommended for people with known risk factors for the condition, such as having a family history of the disease.
The symptoms of coeliac disease can vary widely from person to person. A method that is often used to classify possible symptoms of coeliac disease defines three types of the condition, based on the associated symptoms. These are:
- silent coeliac disease
- minor coeliac disease
- major coeliac disease
These are described in more detail below.
Silent coeliac disease
If you have silent coeliac disease, you will have no symptoms or very mild symptoms. However, damage to your small intestine can still occur, as well as long-term complications, such as osteoporosis (thinning of the bones) or failure to grow at the normal rate.
Minor coeliac disease
In you have minor coeliac disease, you may experience a wide range of minor symptoms. The symptoms are often intermittent (they stop and then start again), and sometimes they can appear unrelated to your diet and digestive symptoms.
Symptoms of minor coeliac disease can include:
- mild abdominal (stomach) pain
- occasional changes in bowel habit, such as episodes of mild diarrhoea or constipation
- anaemia (tiredness, breathlessness and an irregular heartbeat, caused by a lack of iron in the blood)
- loss of appetite
- weight loss
- tingling and numbness in your hands and feet (neuropathy)
- vomiting (usually only affects children)
- some loss of hair (alopecia, usually only affects adults)
Major coeliac disease
In you have major coeliac disease, as well as the symptoms listed above, you may experience more severe symptoms that are caused by your digestive system not properly digesting food (malabsorption).
Symptoms of major coeliac disease include:
- diarrhoea, which can often suddenly occur during the night, resulting in incontinence
- weight loss
- stomach cramps
- muscle spasms
- swelling of your hands, feet, arms and legs, caused by a build-up of fluid (oedema)
Your stools (faeces) may also contain abnormally high levels of fat (steatorrhoea), which can make them foul smelling, greasy and frothy. Your stools may also be difficult to flush down the toilet.
If coeliac disease is left untreated, being unable to digest food in the normal way could cause you to become malnourished.
Although it is not a symptom of coeliac disease, if you have an intolerance to gluten, you may also develop a type of skin rash known as dermatitis herpetiformis. It is estimated that 15-25% of people with coeliac disease also develop dermatitis herpetiformis.
Dermatitis herpetiformis causes a very itchy skin rash that is characterised by blisters. The blisters can burst when you scratch them. The rash usually appears on your elbows, knees and buttocks, although it can appear anywhere on your body.
The exact cause of dermatitis herpetiformis is not known but, as with coeliac disease, the condition is associated with exposure to gluten in your diet. Like coeliac disease, switching to a gluten-free diet should cause the symptoms to clear up.
Coeliac disease is caused by an intolerance to gluten, a protein found in foods such as bread, pasta, cereals and biscuits. Some people with coeliac disease find that eating oats can also trigger their symptoms.
If you have coeliac disease, eating gluten results in damage to your intestines (gut). This happens because coeliac disease is an autoimmune condition.
Autoimmune conditions cause your immune system to mistake healthy cells and substances for harmful ones, and to produces antibodies against them. Usually, antibodies fight off harmful foreign bodies, such as bacteria and viruses.
The surface of the gut lining 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 gut is no longer able to digest all the nutrients you need from the food you eat. This leads to the symptoms of coeliac disease, including diarrhoea and weight loss.
It is not known exactly why people develop coeliac disease, or why some people have very mild symptoms while others have severe symptoms.
However, a number of risk factors have been identified that increase your risk of developing coeliac disease. These are outlined below.
Coeliac disease often runs in families. If you have a close relative who has the condition, such as a parent, brother or sister, your chance of developing coeliac disease is higher.
The risk of developing coeliac disease if you have a close relative with it is approximately 10%, compared with 1% for someone without a close relative with coeliac disease. If you have an identical twin with coeliac disease, there is an 85% chance that you will also develop the condition.
Research shows that 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 other factors must trigger the onset of coeliac disease in certain people, such as environmental factors.
Suggested environmental factors for coeliac disease include:
- previous infection of the digestive system, such as a rotavirus infection (a common cause of stomach infections in children)
- diet during early childhood
A recent UK Government committee looked at the evidence about what effect gluten had in the diet of babies in relation to coeliac disease.
They concluded that there is evidence that introducing gluten into your baby's diet before they were three months old may increase their risk of developing coeliac disease.
Most experts recommended that you wait until your child is at least six months old before introducing gluten into their diet.
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 (a condition where a person has repeated fits or seizures)
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.
Routine screening for coeliac disease is not recommended unless you have symptoms associated with the condition or pre-existing risk factors.
In 2009, the UK National Institute for Health and Clinical Excellence (NICE) issued guidance about when testing for coeliac disease should be carried out. NICE stated that testing for coeliac disease is strongly recommended 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 (those affecting the digestive system, such as nausea and vomiting)
- prolonged fatigue (feeling tired all the time)
- recurring symptoms of abdominal pain
- cramping or bloating
- sudden or unexplained weight loss
- unexplained anaemia
- weight loss
- failure to thrive in infants/toddlers
Testing is also recommended if you have the following conditions:
- type 1 diabetes
- irritable bowel syndrome
- 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
- repeated miscarriages
- Sjogren's syndrome, a condition where the immune system attacks the tears and saliva glands
- Turner syndrome, a genetic condition that only affects women and causes infertility and delayed growth
- unexplained infertility
- unexplained weight loss
Screening for coeliac disease involves a two stage process:
- blood tests to help identify people who may have coeliac disease
- gut biopsy to confirm the diagnosis
These procedures are described in more detail below.
Your GP will take a blood sample and test it for certain antibodies that are usually present in the bloodstream of people with coeliac disease. You should not be avoiding gluten from your diet when the blood test is done as this could lead to an inaccurate result.
However, it is sometimes possible to have coeliac disease and not have these antibodies in your blood. If coeliac disease antibodies are found in your blood, your GP will refer you for a biopsy of your gut.
A gut biopsy is carried out in hospital, usually by a gastroenterologist (a specialist in treating conditions of the stomach and intestines). A gut biopsy can help confirm a diagnosis of coeliac disease.
If you need to have a gut biopsy, an endoscope (a thin, flexible tube with a light and a tiny cutting tool on the end) will be inserted into your mouth and gently passed down to your small intestine. Before the procedure, you will be given a local anaesthetic and a sedative to numb your throat and help you relax.
The gastroenterologist will use the cutting tool at the end of the endoscope to cut away a small piece of tissue from your small intestine. The sample will then be examined in a laboratory for signs of coeliac disease.
Tests after diagnosis
If you are diagnosed with coeliac disease, you may also have a number of other tests to assess how the condition has affected you so far.
You may have further blood tests to check the levels of iron and other vitamins and minerals in your bloodstream. This will help determine whether coeliac disease has led to you developing anaemia (a lack of iron in your blood) due to poor digestion.
If you appear to have dermatitis herpetiformis (an itchy rash that is also caused by gluten intolerance), you may have a skin biopsy to confirm it.
This will be carried out in a similar way to a gut biopsy.
A small skin sample will be taken from an area that is unaffected by the rash so that it can later be examined.
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 that your condition may have started to damage your bones. In coeliac disease, a lack of nutrients, caused by poor digestion, can make your bones weak and brittle (osteoporosis).
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) that is caused by gluten, 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. 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 that your diet is balanced and contains all the nutrients you need, including essential vitamins and minerals.
If you have coeliac disease, you will no longer be able to eat any foods that contain wheat (farina, graham flour, semolina, durum cous cous and spelt ), barley or rye.
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.
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. However, if you are unsure, use the lists below as a general guide.
Foods containing gluten (to avoid)
If you have coeliac disease, do not eat the following, unless they are labelled as gluten-free:
- 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 items, 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 (to include)
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 marinated)
- gluten-free flours, including rice, corn, soy and potato
The Coeliac Society of Ireland is the country's leading charity supporting people who are living with coeliac disease. Their website contains information and advice about living with the condition, including gluten-free recipes.
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.
If you have coeliac disease, it can cause your spleen (a small an organ behind the stomach) to work less effectively, making you more vulnerable to infection from certain germs.
Therefore, you may need to have several vaccinations, including:
- flu (influenza) jab
- HIB/MenC vaccine, which protects against sepsis (blood poisoning), pneumonia (an infection of the tissue of the lungs) and meningitis (an infection of the lining of the brain)
- pneumococcal vaccine, which protects against infections caused by the Streptococcus pneumoniae bacterium
As well as cutting gluten out of your diet, your GP or dietitian may also recommend that you take vitamin and mineral supplements, at least for the first six months after your diagnosis.
This will ensure that 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 may clear it. 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 that 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.
If you don’t cut gluten from your diet, your symptoms will return
Even if you only consume a small amount of gluten such as a spoonfull of pasta, you may have very unpleasant gastrointestinal symptoms, such as cramps, vomiting and diarrhoea. If you keep consuming gluten regularly, you will also be at greater risk of osteoporosis and bowel cancer in later life.
Oats do not contain gluten, but many people with coeliac disease avoid eating them because sometimes 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 that the oats are pure and that there is no possibility that contamination could have occurred.
It is recommended that 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.
Should I give my child gluten?
If you have coeliac disease and have a new baby, do not introduce gluten into the baby’s diet before six months. Breast milk is naturally gluten free and all infant milk formulas are too.
It is recommended that gluten-containing foods be introduced gradually when a child is six months old, and the situation carefully monitored.
If you have coeliac disease that is untreated or undiagnosed (you are still eating gluten), several complications can occur. If you have coeliac disease, it is crucial that you do not eat any gluten.
It is a common misconception that eating a little bit of gluten will not do you any harm. Eating even tiny amounts can cause the symptoms of coeliac disease and increase your risk of developing the complications outlined below.
Osteoporosis is a condition that causes your bones to become brittle and weak. Your bones need a wide variety of vitamins and minerals to stay dense and strong.
If you have coeliac disease, you have an increased risk of developing osteoporosis due to the effect on your digestion. The damage gluten causes to your intestines (gut) prevents enough nutrients being absorbed into your bones from the food that you eat.
Osteoporosis can be treated with supplements that strengthen the bones, such as vitamin D and calcium. More severe cases of osteoporosis may require medication.
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.
If you have coeliac disease, you are more likely to also develop lactose intolerance, a reaction to milk sugar (lactose) that is found in dairy products. Lactose intolerance causes symptoms such as bloating and abdominal discomfort. The damage to your digestive system, caused by gluten, may also make it difficult for you to digest lactose.
Lactose intolerance can be effectively treated by not eating and drinking dairy products that contain lactose. You may also need to take calcium supplements because, as dairy products are an important source of calcium, you will need to compensate for not eating them.
Some research has suggested that having coeliac disease can increase your risk of developing certain types of cancer, including:
- bowel cancer
- lymphoma (cancer of the lymphatic system, which is part of the immune system)
The same piece of research found that people with coeliac disease have a lower risk of developing lung and breast cancer, although the reasons for this are unclear.
It is estimated that people with coeliac disease are twice as likely to develop bowel cancer compared with 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 off 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:
- bloody or black stools (faeces)
- weight loss
- abdominal (stomach) pain
- lymphoma, which includes symptoms such as painless swellings in your neck or armpit, unexplained fatigue and night sweats.
See your GP if you develop these symptoms.
The most important thing to do when you have been diagnosed with coeliac disease is to switch to a completely gluten-free diet, and stick to it for life.
Keep up-to-date and be vigilant regarding issues such as food labelling, as it can be easy to let your guard slip once you have fully recovered. When eating out, it's advisable to call restaurants in advance to check whether the chef can safely cater for you. Thanks to the advocacy work of Coeliac Society of Ireland, many restaurants are now aware of the seriousness of the condition and are able to provide gluten-free meals.
Exercise is important, not only for your wider health benefits, but also because it strengthens the bones, which is important if your body has not been getting enough calcium.
Avoid smoking as it is associated with a lower bone density in both men and women. You can drink, but within the guidelines of 14 units weekly for women, and 21 for men. Beers and lagers are not gluten-free, although some gluten-free beers are now available.
Naturally gluten-free foods:
- Rice, millet, maize, quinoa, amaranth and buckwheat, and flours, cereals and products based on them, such as popcorn and rice cereals - (these flours and grains are naturally gluten free but if they are milled in a factory that handles gluten containing cereals, there is a high risk of cross contamination. The Coeliac Society’s Food List should be checked for reliable brands of these flours and grains.)
- All vegetables, fruit, nuts and seeds.
- All meats, fish and shellfish.
- Dairy products, such as milk, yoghurt, cream and cheese.