[Susan Cardillo C]

Hello:
Julie(St. Bernard) had a bad bout of IBD around 5 years ago. Since, she has been religiously on Royal Canin HP. Recently(she is now 9 years old) and after getting Bloat this summer(successful surgery to fix), she has her IBD back, worse then before.
The vet suggested Purina Pro Plan HA- we did the canned food for two weeks and it was really working to solidify her poop. We introduced the kibble(same brand and flavor) about 3 days ago and now she has reverted back to total diarrhea.
Has anyone else had issue with kibble? I have stopped giving it to her, but she loves it…now she can only have the cans and she is eating 8 cans a day!
Would love some insight.
Thanks
Susan