How long does a blood test take to work for coeliac disease?

Coeliac blood tests look for immune markers linked with a reaction to gluten. The result is interpreted alongside symptoms, family history, diet, and sometimes other tests. A positive blood test does not by itself describe the amount of bowel injury, while a negative result can be less informative if gluten was already removed or reduced. Your clinician will explain whether specialist assessment is needed.

Ask when the laboratory report is expected and follow the testing instructions. Unless your clinician has told you otherwise, do not begin a gluten-free diet before the assessment is complete, because reducing gluten can affect the usefulness of testing. Mention weight loss, diarrhoea, bloating, tiredness, mouth ulcers, anaemia, medicines, and any close relative with coeliac disease.

Seek urgent help for severe dehydration, fainting, vomiting blood, black stools, severe abdominal pain, or breathing difficulty. Arrange prompt review for ongoing weight loss, persistent diarrhoea, marked weakness, or trouble eating and drinking while results are pending.

Ask which coeliac markers were tested, when the report should arrive, whether you should continue eating gluten, and what further assessment follows an abnormal result.