Coeliac disease

What coeliac disease is

Coeliac disease is an immune reaction to gluten, a protein in wheat, barley, rye and oats. In people who are genetically susceptible, gluten triggers inflammation that damages the lining of the small bowel and reduces its ability to absorb nutrients. About one in 70 Australians has it, but only around one in five of those have been diagnosed.

It is not an allergy and not the same as gluten sensitivity or intolerance. It runs in families: parents, brothers, sisters and children of someone with coeliac disease have a much higher chance of having it too and should be tested.

The symptoms, including the ones outside the gut

Some people have obvious gut symptoms: diarrhoea, bloating, wind, abdominal pain or weight loss. Many do not. Coeliac disease can show up instead as:

• iron deficiency that does not respond to tablets
• tiredness, low vitamin B12 or folate
• early osteoporosis
• abnormal liver tests
• an itchy blistering rash called dermatitis herpetiformis
• symptoms that have been put down to irritable bowel syndrome

How it is diagnosed

• Blood tests: tissue transglutaminase antibodies, with total IgA to make sure the result can be trusted, and sometimes other antibodies.
• Gastroscopy with biopsies from the duodenum confirms the diagnosis. It is a short procedure under sedation. There is more on the gastroscopy page.
• Gene testing for HLA-DQ2 and DQ8 cannot diagnose coeliac disease, but a negative result makes it very unlikely. It is useful when gluten has already been stopped or when the other tests disagree.

How coeliac disease is treated

The treatment is a strict gluten-free diet for life. There is no safe amount of gluten for someone with coeliac disease, even without symptoms, because the damage continues. A dietitian experienced in coeliac disease makes an enormous difference, particularly in the first months.

Most people feel better within weeks, although full healing of the bowel lining can take much longer in adults.

Follow-up

Follow-up checks that the diet is working and looks for the complications of coeliac disease:

• repeat antibody tests, which should return to normal on a strict diet
• a follow-up gastroscopy with biopsies at about 12 months, to confirm the bowel lining has healed
• iron, vitamin B12, folate, vitamin D and calcium
• a bone density scan, as bone thinning is common at diagnosis
• vaccination against pneumococcus, as coeliac disease can reduce the spleen's function
• testing of first-degree relatives

If symptoms persist or come back despite the diet, the most common reason is gluten getting in unnoticed. Other conditions that travel with coeliac disease, such as microscopic colitis, lactose intolerance or bacterial overgrowth, are also considered, and an earlier repeat gastroscopy may be needed.

Where coeliac disease is diagnosed in Sydney

A/Prof Viraj Kariyawasam is a consultant gastroenterologist and hepatologist. Coeliac testing, confirmation and follow-up are handled at consultation in Norwest, Rouse Hill, Pennant Hills and Macquarie Park.

The gastroscopy with duodenal biopsies is performed at Norwest Private Hospital, Macquarie University Hospital and Pennant Hills Day Surgery. A referral from your GP is needed for a consultation.