M.R.
Look at the web site for the Celiac Foundation, a nonprofit that has information about the disease: http://celiac.org
Also go to the National Institutes of Health web site and search for celiac:
www.nih.gov
Please do any web searching with care. These are reputable sites, but there are nutty sites out there for almost any disease, sites that can mislead you with promises of "cures" or claims that the condition is caused by this or that, usually things that the site then promises it can fix for you--for a price.
But first I'd wait until you have a diagnosis - you don't, yet, and could end up worrying yourself unnecessarily, or doing research that you don't need. Stick with the doctors, push to get your child all tests the doctors recommend ASAP, and go from there. Any good doctor is going to send you immediately to a registered dietitian or nutritionist as part of the treatment, if it's celiac.
Celiac is serious -- we don't have it our family but my friend's husband nearly died some years back because doctors failed to diagnose his celiac. When he was finally diagnosed, he made a comeback and your son can too.