I totally can't have anything the hospital offers. It's part of being allergic to more than just gluten.
Reed's soda is gluten free, they make many different flavors. They have a website, you can call, email, ask questions, find one that your body is okay with so the next time your in the hospital you have back up! Prepare for the stupid people in your life. Stand firm with what you know.
I tupperware homemade food where ever I go. Got Intolerance Enzyme complex pills and Gluten enzyme pills for just the situation where somebody gluten's me. Especially my kids. Hands and toys get in my mouth.
I'd be totally running out that hospital in my gown with the back out!
I hope your surgery went just fine.