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What is Coeliac Disease?

Coeliac disease is a permanent, autoimmune disorder that causes a reaction to gluten which is found in wheat, barley, rye and oats. 

Coeliac disease (pronounced see-lee-ak) is a permanent intestinal reaction to dietary gluten. In coeliac disease the cells lining the small bowel (intestine) are damaged and inflamed. This causes flattening of the tiny, finger like projections, called villi, which line the inside of the bowel. 

The function of the villi is to break down and absorb nutrients in food. When these villi become flat, the surface area of the bowel is greatly decreased, which interferes with the absorption of nutrients from food. This may lead to deficiencies in vitamins (such as folic acid) and minerals (e.g. iron and calcium).

Coeliac disease is hereditary, however both genetic and environmental factors play important roles in coeliac disease.

It is currently estimated that 60,000 to 70,000 New Zealanders have coeliac disease (1 in 70), however up to 80% of those are unaware they have the condition.


The symptoms of coeliac disease vary considerably. Listed below are some of the commonly reported symptoms which may occur alone or in combination:

Common in adults:

  • Diarrhoea – This may begin at any age and is often present for years prior to diagnosis. It may first appear after other illnesses (e.g. gastroenteritis) or abdominal operations
  • Fatigue, weakness and lethargy
  • Anaemia – iron or folic acid deficiency are the most common. The anaemia will either not respond to treatment or will recur after treatment until the correct diagnosis is made and a gluten free diet is commenced
  • Weight loss
  • Chronic constipation – some are more likely to experience constipation rather than diarrhoea
  • Flatulence and abdominal distension
  • Cramping and bloating
  • Nausea and vomiting
  • Osteoporosis (thin bones)

Less common in adults:

  • Easy bruising of the skin
  • Ulcerations and/or swelling of mouth and tongue
  • Miscarriages and infertility
  • Muscle spasms due to low blood calcium levels
  • B12, A, D, E and K vitamin deficiency
  • Skin rashes such as Dermatitis Herpetiformis
  • Neurological issues
  • Difficulty concentrating
  • Bone and joint pains

Common in children:

Symptoms do not occur until gluten is introduced into an infant diet – later onset is also possible.

  • Large, bulky, foul stools
  • Diarrhoea 
  • Chronic constipation
  • Poor weight gain
  • Weight loss in older children
  • Chronic anaemia
  • Poor growth or poor height gains
  • Abdominal distension, pain and flatulence
  • Nausea and vomiting
  • Irritability


Coeliac disease is treated by a life-long gluten free diet. By specifically removing the cause of the disease, this treatment allows all abnormalities, including the lining of the small bowel to recover completely. As long as the diet is adhered to strictly, patients should recover. An initial few weeks on both a gluten free and lactose free diet  (to lower the lactose sugar intake) may be warranted, as this will allow the bowel lining to recover and replace its normal quantity of the enzyme 'lactase', which digests lactose sugar prior to absorption. In a small number of people with coeliac disease the enzyme may be slow to recover and the need for a low, or no cow’s milk, diet may be needed for longer period of time.

This information is for guidance only and should not replace advice given by your medical professional. 

Download our 'Consider Coeliac Disease brochure' from our 2016 Mediboard campaign:

Consider Coeliac Disease Brochure Consider Coeliac Disease Brochure (5623 KB)