My 16 yo DS has a history of poor growth and is trailing along the 0.2 centile for both height and weight. He has always eaten extremely well, to the point that relatives and friends are constantly surprised by the amount he puts back compared to his size. He’s under a paediatric endocrinologist, has the correct levels of growth hormone, did fine in the glucagon test etc and I am assuming did not test positive in the coeliac blood test. However I think we are missing something - he’s always had very loose stools and very fatty or junk food from McD’s etc goes straight through him. Would it be acceptable to push for an endoscopy to do the biopsy to at least exclude coeliac disease? I understand there’s a significant rate of false negatives in the serological test - is that correct? He’s desperate for answers now and I’d really like to help him.