My vet keeps telling me that Purina is the brand she prefers and recommends now. She told me to get Ripley Purina Pro Plan for Sensitive Skin and Stomach and it's working great for him. He stopped having stomach issues all the way around (meaning from both ends). It actually is more expensive than the Nutro I'm feeding all the other cats but it's well worth it. I would just put all my cats on it but Scout and Decker don't seem to like it as well and Jazz is so picky that she wants change frequently.