Celiac disease and gluten sensitivity can mimic many different diseases and, I have discovered through fifteen years of researching and managing patients, it is best to test everyone. In Japan and Italy they test all children before the age of 6 because they are aware of the high morbidity and mortality that comes with undiagnosed celiac/gluten sensitivity.
On Hartke is online I found an informative article on the warning signs of celiac disease and a video interview of Dr. Peter Jo that's well worth watching. Dr. Peter Jo is a Reston, Virginia based chiropractor and certified nutritionist who is knowlegeable on the subject.
Read more about what he has to say about celiac disease, testing, the in's and out's and more at his blog.
I repeat myself when I say that I use Dr. Kenneth Fine's lab called http://www.enterolab.com/ for testing.