Glad you ruled out a blockage! That's always one of my fears.
Hopefully some good meds will get things operating smoothly again.
I'd look at some good probiotic and enzymatic supplements - check with the vet if you're still on meds, though - to help with digestion.
I like the "Now Fresh" foods for kibble - you can get chicken free versions (something I look for). Made in Canada. That, or one of the Orijen or Acana limited ingredient varieties might be a good option. Blue Buffalo has had some recent recalls, that might make me suspicious. One was for mold... that might cause some intestinal issues... hopefully nothing that won't resolve with love, care, and time.