Any suggestions on the best way to go about testing my 6 month old twins for Celiac?

First, some background info. The vast majority of my immediate family has been diagnosed with Celiac, either by biopsy or the elimination diet. Some of my husband's family members have it as well. I have 6 month old identical twin girls, and I strongly suspect they have Celiac as well. They have begun to eat solid foods, but I have not given them anything containing gluten. A month ago I tried giving them Highland's teething tablets for teething pain, and they had what appeared to be a violent reaction to them. They are mostly corn starch, and I have an extreme sensitivity to corn, so thus far I've assumed they do too. They had stomach pain which caused them to hunch forward, they were crying and completely inconsolable for hours. Their bowel movements also became infrequent and painful for a few days after that. I know some of the tests require you to eat gluten in order to be accurate, but I don't wish to make them eat something that could cause so much pain. My reactions are extraordinarily painful and violent, and I don't want them to go through the same thing if they don't have to. I'd love to hear ideas on the best way to go about testing them, and about any experiences anybody else has had with their kids.