Coeliac Disease

Q: How is it diagnosed? Keep eating gluten!

Diagnosis has two steps: a blood test (coeliac serology — usually tissue transglutaminase antibody) followed by gastroscopy with small bowel biopsies to confirm. Both tests only work if you are eating gluten — going gluten-free beforehand causes false negative results. If you have already reduced gluten, we will advise a 'gluten challenge' (generally the equivalent of about 2 slices of wheat bread daily for at least 6 weeks) before testing. A gene test (HLA-DQ2/DQ8) is sometimes useful: a negative result virtually rules coeliac disease out, but a positive result alone does not diagnose it.

ShoreGastro
2 days ago
2 min read

An immune condition triggered by gluten

What is coeliac disease?

Coeliac disease is a condition in which the immune system reacts abnormally to gluten — a protein in wheat, rye and barley — causing inflammation and damage to the lining of the small intestine. This impairs absorption of nutrients. It affects about 1 in 70 Australians, though most remain undiagnosed. It is not a food allergy or a simple intolerance, and it is lifelong.

Symptoms — often subtle

Gut symptoms: diarrhoea, constipation, bloating, wind, abdominal pain, nausea
Fatigue and low iron (or other nutrient deficiencies) — sometimes the only clue
Weight loss, mouth ulcers, an itchy blistering rash (dermatitis herpetiformis)
Osteoporosis, unexplained infertility, or abnormal liver tests
Some people have no symptoms at all and are found through family screening

How is it diagnosed? Keep eating gluten!

Diagnosis has two steps: a blood test (coeliac serology — usually tissue transglutaminase antibody) followed by gastroscopy with small bowel biopsies to confirm. Both tests only work if you are eating gluten — going gluten-free beforehand causes false negative results. If you have already reduced gluten, we will advise a 'gluten challenge' (generally the equivalent of about 2 slices of wheat bread daily for at least 6 weeks) before testing. A gene test (HLA-DQ2/DQ8) is sometimes useful: a negative result virtually rules coeliac disease out, but a positive result alone does not diagnose it.

Treatment — a strict, lifelong gluten-free diet

The only current treatment is complete, lifelong exclusion of gluten: no wheat, rye, barley (and oats initially — discuss with your dietitian)
Even small, occasional amounts of gluten cause ongoing bowel damage, whether or not you feel symptoms
Watch for hidden gluten in sauces, stocks, processed meats and medications; take care with cross-contamination (shared toasters, butter knives, fryers)
In Australia, foods labelled 'gluten free' meet a strict standard and are safe
See an accredited practising dietitian experienced in coeliac disease, and consider joining Coeliac Australia for practical support

Follow-up matters

With a strict gluten-free diet the bowel heals and long-term risks (osteoporosis, nutrient deficiency, rarely small bowel lymphoma) fall substantially. We recommend regular review with repeat serology, checks of iron, B12, folate and vitamin D, a bone density scan where indicated, and sometimes a follow-up biopsy to confirm healing. First-degree relatives (parents, siblings, children) have about a 10% chance of coeliac disease and should be offered screening.

—

This information is general and not a substitute for personalised medical advice. Please discuss any questions with your gastroenterologist or GP. If you develop severe symptoms, call 000 or go to your nearest emergency department.