Pre -Op nightmare!

On fri. we went to Aydens ped. for his pre-op physical,everything was fine He was laughing & playing & happy.When we were done his ped. said"ive never seen him drink before can I see?"So he gives him a Dixie-cup full of water & Ayden happily drinks it & asks for more.We we on our way to the car,not even 5 min. later he was srceming in pain,shaking & his body was tensing up saying"help me momma,my belly hurts really bad!".We've never seen him in so much pain before.We run back up to the ped. & aydens freaking out & the Ped. quickly gives him something like benadryl,said it takes 20 min. to work,but Ayden was in so much pain he said head for the ER.We were so scarred we went through 4 red lights,shortly after getting there he was fine.So now his ped. thinks it was an allergic reaction to the wax on the cup & tells us to stay away from it until we can find out for shure.Its just our luck to have this happen,Im telling you we need a break!!!!!!!So please pray things will be smoother from here on out.First thing he said when he woke up the next day was "mommy,my belly feels all better" & now hes back to his playful crazy self,Thank God!!!!!!