I too would suggest ELISA ACT testing. It will give you all of the foods she is allergic to. You could get her genetic testing done, but it isn't as difinitive and ELISA. I found out my genes when I had the enterolab stool test done, it wasn't difficult to read at all. It gives you a description of what the genes mean. If you look in this forum under weightloss not happening. I posted my results, so you could see what the enterolab results look like. You can test for foods on enterolab, but I don't think corn is one of them. Good luck with all of this, I can't imagine being in your shoes. Your poor daughter that is just awful! I would definitely talk to your doctor and see about getting allergy testing!
As Jackie said, please keep us posted!
Praying for you and your daughter,