Is it Coeliac Disease OR Gluten Intolerance?

Many people will tell us that they simply feel better when they don’t eat gluten.

Gluten is a protein found in wheat, barley and rye and many find that when they omit gluten from their diet, that their symptoms subside.


Could it be Coeliac Disease or is it Gluten (wheat) Intolerance?


It can be hard to know, as both coeliac disease and gluten (wheat) intolerance present with similar symptoms like, abdominal pain, bloating, diarrhoea, constipation, fatigue, headaches, nausea, vomiting, skin conditions and joint pain. There is increasing evidence of symptoms such as anxiety and feelings of depression too. The severity of symptoms will vary from person to person for both conditions. A lot of patients with coeliac disease do not have symptoms.



Why is it important to know?


If the symptoms go away when you stop eating gluten, wouldn’t you just omit gluten from your diet? Do you need an actual diagnosis? The answer is YES.

It is important to have a definitive diagnosis, because both conditions are quite different in terms of the long-term implications.



Let’s start by explaining the difference between the two conditions.


Coeliac Disease


In coeliac disease, the presence of gluten stimulates the immune system to attack the lining of the small intestine. The resulting damage to the intestines is called villous atrophy. As coeliac disease is autoimmune in nature, the gluten doesn’t directly cause the damage, instead it triggers the immune system to cause the damage. This is particularly worrying, as it means the body is unable to properly absorb much-needed nutrients and minerals when food is digested.


Whilst there is no cure for coeliac disease, following a strict gluten-free diet is recommended as it helps minimise symptoms and keep the condition at bay. This is vital, even if symptoms are very mild, as even the smallest amount can have detrimental effects on the body.


These long- term risks include osteoporosis, other autoimmune conditions such as thyroid disease, type 1 diabetes and rheumatoid arthritis. Coeliac disease may also contribute to the development of anaemia (low blood count), micronutrient deficiencies (e.g. iron, folate, B12, calcium, vitamin D), malnutrition, depression, infertility, and even cancer, if left untreated. The long-term risks resolve on a strict gluten free diet.


Knowing the diagnosis will mean that appropriate medical assessments can take place.


Gluten (Wheat) Intolerance


With gluten (wheat) intolerance, the mechanism is poorly understood, but it is thought that there is a direct reaction to wheat, gluten or even the carbohydrates (FODMAPs) in wheat during the process of digestion, causing abdominal symptoms. There is still no actual ‘test’ for gluten (wheat) intolerance, and scientists are yet to determine the root cause of the condition.


Unlike people with coeliac disease, people with a gluten (wheat) intolerance may find they can tolerate a small amount of gluten in their diets, and there are no long term heath problems.




Testing for coeliac disease is a 3 step process


1. The Gluten Challenge


It is important to be on a normal diet (including gluten) for 6 weeks prior to testing. The Gluten Challenge requires adults to eat a minimum of 4 slices of wheat based bread (or equivalent) each day. The amount is halved for children.


2. Screening using a blood test


The coeliac serology (blood test) measures antibody levels in the blood, which are typically elevated in people with untreated coeliac disease, due to the body’s reaction to gluten. Immediate relatives of those diagnosed with coeliac disease should also be screened.

A diagnosis of coeliac disease should not be made on the blood test alone. A positive blood test always needs to be followed by a small bowel biopsy to provide a definitive diagnosis. Also coeliac serology is negative in 5-10% of patients with coeliac disease.


3. A small bowel biopsy is essential to confirm diagnosis


This involves a gastroscopy, which is a simple day procedure performed whilst under a light anaesthetic sedation. During this procedure, several tiny samples (biopsies) are taken from the small bowel. These biopsies are examined under a microscope to confirm the presence of villous atrophy (damage to the intestinal lining). If positive for villous atrophy, then the diagnosis for coeliac disease is positive.


If the biopsy is negative for villous atrophy, you do not have coeliac disease even if the serology is positive (false positive serology occurs in 3-5% of people). There may be other reasons for your symptoms, one if which could be Gluten (wheat) Intolerance.


In addition, there’s gene testing


Gene testing (HLA genes) may be useful only in select cases where the diagnosis of coeliac disease is unclear. It is performed on a blood test by your doctor. The gene test on its own cannot diagnose coeliac disease. If the gene test is positive, confirmation of coeliac disease still requires serology and a small bowel biopsy.


Gene testing can be helpful if you have symptoms but the coeliac serology is negative. If the gene test is negative it effectively rules out coeliac disease.



In Summary


It is important to know if you have coeliac disease because it is imperative that you stick to a gluten free diet and are assessed for possible complications of this condition for the long term. If managed effectively, those with coeliac disease manage very well. If you do not have coeliac disease, your doctor may investigate further to rule out other conditions, but may confirm that it is in fact gluten (wheat) intolerance. However, before cutting anything out, it’s important sufferers check in with their GP first to make sure it’s gluten causing the reaction and not another condition entirely, such as irritable bowel syndrome.


For further information on coeliac disease or other gastroenterological conditions please visit

If you have been referred for a gastroscopy to confirm coeliac disease please call us on 9468 9700.



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