Glad to hear Zeddie is doing better!
Fingers crossed that she continues to eat her new food.
My little Mickey has a sensitive stomach, and I have had good luck with cooking for him. He does well with rabbit; I freeze the meat, then will cook to about 50% done, and then slice some and food processor the rest. I give him a little bit to lick off of my fingers, then work up to slices of meat. He will eat it even when he isn't feeling well. When is is ok, I can sometimes get him to eat chicken or wild boar prepared the same way.
For diahrea I mix in some rice flour to the food processored meat, along with home made broth.
This is my version of upset tummy kitty food.