Poor Poppy. I'm glad they finally found out what all her troubles were though. Flagyl should help a lot with the diarrhea and inflammation.
I would call your insurance as well, although unfortunately I think they will probably consider it a pre-existing condition, but all policies are different so it wouldn't hurt to ask. (Lucky had chronic diarrhea/colitis as a puppy too and subsequent vet visits for the same thing were excluded because he was taken in during the waiting period for the policy to take effect)