Coeliac disease is described as an 'iceberg' condition as only 24 per cent of people who have it are believed to have been diagnosed. For every one person diagnosed, seven to eight people remain undiagnosed.
In people suffering with coeliac disease the immune system mistakes gluten as a threat and attacks it. This process also causes damage to the lining of the small intestine as the villi, tiny finger-like projections that line the gut, become flattened and can't absorb nutrients. If left undiagnosed, coeliacs are at risk of malnutrition, vitamin and mineral deficiencies and the fragile bone condition osteoporosis.
Abdominal pain, vomiting, diarrhoea, bloating, wind, indigestion, constipation and bloating are all symptoms of coeliac disease.
Other symptoms may include: extreme tiredness caused by malabsorption of nutrients, potentially leading to iron, vitamin B12 or folic acid deficiency or anaemia. Mouth ulcers, alopecia (hair loss), tooth enamel damage, fertility problems, and tingling and numbness in the hands and feet are also symptoms of the disease. It's also possible to have no symptoms at all.
Babies with coeliac disease may vomit repeatedly and have chronic diarrhoea, which can lead to their stomachs becoming swollen. A common sign is that they are not be able to put on weight or grow as fast as expected, whereas symptoms in older children include poor growth and delayed puberty, however, most adults with coeliac disease do not lose weight and are not underweight.
A raised, red (often blistered) skin rash, called dermatitis herpetiformis, is another symptom and affects one in 3,300 people.
The average time it takes to be diagnosed with coeliac disease is 13 years. This is because the symptoms can be vague and confused with other conditions including irritable bowel syndrome (IBS).
Coeliac disease is diagnosed by a blood test which looks for antibodies to gluten and must be confirmed by a gut biopsy to check for damage to the villi that line the intestine.
If you have the symptoms described, don't stop eating gluten before you have been tested. This is because tests look at how the body responds to gluten and if you have been avoiding gluten the antibodies won't show up.
Who gets coeliac disease?
One in 100 people are estimated to have coeliac disease. Coeliac disease affects men, women and children, although diagnosed cases are two to three times higher in women than in men. It is most commonly diagnosed in people between the ages of 50 and 69, but can be diagnosed at any age.
People who have a first degree relative (biological parents, children or siblings) diagnosed with coeliac disease have a four to 17 per cent increased risk of developing it. Auto-immune conditions such as type 1 diabetes, arthritis and auto-immune thyroid disease also put you at increased risk and those with Down’s Syndrome are also more prone to the condition.
Avoiding all foods containing gluten will cause your symptoms to disappear after a few weeks, although it can take up to two years for your gut to heal completely. Remaining gluten-free for life though is vital as just a tiny amount can sensitise the gut again and symptoms can flare up.
Foods to avoid include barley, bran, bulgur, couscous, malt extract, rye, semolina, wheat germ and wheat starch. Oats need to be avoided too because of the risk of cross contamination from other grains.
Gluten-free versions of almost all foods are available now including, bread, pasta, cakes and biscuits. Plenty of foods are naturally gluten-free including brown rice, potatoes, sweet potatoes, pulses, nuts and seeds, fruit and vegetables.
You may also be advised to take vitamin supplements (commonly calcium and iron) for around six months to help restore any deficiencies. In a small number of people, symptoms persist despite avoiding gluten, this is known as refractory coeliac disease and you will need referral to a specialist centre.