If you have a positive blood test for coeliac disease, your GP will refer you to a gut specialist – a gastroenterologist – for a biopsy of the gut. This confirms whether or not you have coeliac disease.
A biopsy involves a small camera called an endoscope being passed through your mouth and stomach into the gut. It is done using an anaesthetic spray to numb your throat, or with a sedative given by injection.
Biopsies are collected and examined under a microscope to check for damage to the gut lining, which is typical of coeliac disease.
These tests for coeliac disease can be done on both adults and children. In young children, the endoscopy is performed under a general anaesthetic. In some cases, though, an endoscopy might not be carried out on children. Read more about diagnosis.
If you have any concerns about testing, the best thing to do is to talk with your healthcare team.
Classification of biopsy results
In people with coeliac disease there is damage to the lining of the intestine. Your healthcare professional will classify the damage according to a scale called the Marsh classification:
- Marsh 0: the lining of the intestine is normal and it’s unlikely that the person has coeliac disease.
- Marsh 1: increased number of lymphocytes (small white blood cells that are involved in the body’s immune system response to the disease) is seen, but there are normal villi.
- Marsh 2: increased number of lymphocytes, the depressions in the lining of the intestine are deeper than normal but normal villi length.
- Marsh 3: the villi are becoming flattened.
- Marsh 4: the villi are completely flattened.