Allergies do not give you stomach pain. They cause histamine responses.
You may wish to read about the differences between allergies and intolerances and CELIAC . Contrary to what people say, Celiac is not a "gluten allergy".
I am not sure what you think you will gain from allergy testing.
Corn is difficult for many people to digest, especially in a gut that is ravaged by celiac.
I always had stomach and abdominal pain after eating corn (my favorite veg) and now, I do NOT!
Take out any foods that give you grief. Let your gut heal and try the food again in a few weeks.
It takes time to recover from the damage done in celiac.
"Life is not the way it's supposed to be. It's the way it is. The way we cope with it makes the difference." Virginia Satir
"The strongest of all warriors are these two - time and patience." Leo Tolstoy
"If you want to lift yourself up, lift up someone else" Booker T. Washington
“If idiots could fly, the sky would be like an airport.”― Laura Davenport
"LTES" Gem 2014
Misdiagnosed for 25+ years; Finally Diagnosed with Celiac 11/01/10. Double DQ2 genes. This thing tried to kill me. I view Celiac as a fire breathing dragon --and I have run my sword right through his throat.