My husband started going to a foodbank in our neighborhood a few months ago. It is a once-per-month thing. Anyway, typically they don't let folks go through - they just give you a box (actually, many boxes) of food to last the month. My husband told them that I had Celiac and need to be gluten free, and they let him walk through. He got tons of Amy's soups and some Whole Foods stuff. Now he always gets to walk through. So I know it is really hit and miss as to what person you get, but hopefully you'll find someone with a kind heart who will let you walk through and look for gluten-free stuff.
And on a bigger note, shouldn't we be doing something about this in our communities? Like writing letters to our food bank organizations and such. I'm going to write a letter to the Oregon foodbanks and just ask that folks be educated that people with Celiac Disease and other food sensitivies may need to be able to choose their own food. And maybe volunteer at foodbanks to help sort food by intolerance? I don't kow, but this problem is only going to become bigger, as the economy is not improving quickly and more and more people are being diagnosed.
Good luck to you.