Vet decided it must be IBS. It never occurred to any of us that it was the food. After reading similar reviews however we stopped feeding the kitten Purina Pro Plan and resumed the previous brand.

I've had my 3 cats on Purina One Tender Selects for ... At 3am on New Year's day I found my smallest cat who didn't have any other symptoms from the food limp in the hallway struggling to breathe.