Q: My friend's brother-in-law is 33 years old and is suffering off and on from diarrhoea. Some years ago he was diagnosed as having food & milk allergy as upper GI endoscopy and biopsy done twice were normal. He takes antibiotics to control it. Now doctor has advised another endoscopy and biopsy to rule out celiac disease. Another thing is that he is very afraid of endoscopy because it give him pain. Somebody told him that after under going it so many times he will develop comlications like GI bleeding or rupture of stomach or weakness of the system. Is that true and do repeat biopsy and endoscopies have any side effects even if done properly? His tests like anti-endomysial antibodies, antitransglutaminase IgA, D-xylose, CBC, etc are normal. Are there any other non-invasive techniques to detect celiac disease? Do the above normal test results not exclude celiac disease? Please suggest the appropriate treatment and advise.

A:Thank you for your question about your friend, who, as I understand is suffering from chronic diarrhoea. The cause for most diarrhoeal illness is in the small or large bowels and the investigations should be concentrated in these areas. Most important cause in the tropics is due to infections and parasites and stool examination is vital. After excluding these, investigations lilke barium examinations of the small and large bowels as well as colonoscopy may be needed. Endoscopy of the stomach and duodenum has limited value except in diagnosis of coeliac disease where duodenal biopsy is 100% diagnostic. In your friend's case it is unlikely, as his blood for the relevent antibodies has been negative. But it should be recognised that the gold standard for diagnosing celiac disease is duodenal biopsy as very rarely the antibody levels may not be high. I suggest you seek an experts opinion locally.