What Next - Negative Blood Test?

[GFLife]

One of my friend's has a 4 year old son that has had chronic diarrhea for 6 months. They have done the TTG test which was negative and are scheduled to see a GI next week(the same GI that diagnosed my daughter so is familiar with Celiac Disease). Anyway, my friend's family has a history of Celiac Disease and believe that her son may have it too. They are hoping that the GI schedules an endoscope. My question to you is this, if an endoscope is performed what additional tests should she recommend for her son? I've seen the Vitamin D and Iron deficiency suggestions but do you have any other suggestions.

Thanks for your help!

[mushroom]

If he is a good GI he will know that testing results are not very reliable in small children. There are several other blood tests that can be run - the EMA and the DGP probably being the most likely to show up something - and the scope to check for intestinal damage, but these can all be negative and not mean that he does not have it, unfortunately. Yes, blood tests to check for nutrient levels (full metabolic panel, CBC, all vitamin levels, iron/ferritin, zinc, magnesium) should be done. Apart from that, if he tests negative the only other thing to be done is to try him on the gluten free diet and see how he responds.