My little lady always seams to have something going on, She needs a break!!!!

Over the last two months my girl has been questioned for liver problems and pre-leukemia (thankfully all cleared her first blood test came back with scary results - further investigation found no serious issues) but she was diagnosed with Post Viral Fatigue (same as chronic fatigue).
Then today we had an appointment with her Paediatrician and now he is questioning ceoliac's.

I have been looking into it and I do seam to think he may be right. She has some of the symptoms - she has always been a tired kid (and now she has the PVF), goes between constipation and large poo's, She went through a patch of unexplainable vomitting (which stopped when we removed gluten as part of a low chem diet - but hasn't returned when gluten was reintroduced), she is very underweight and hasn't gained any weight over all for 18 mths and she is almost 16 and has not hit puberty yet. She also has an allergy to dairy which from what I read is common with a gluten allergy.

I am thinking as I write this I need to get the test done sooner rather then latter.

Any tips for starting out with ceoliac?