I rescued a kitten 2 months ago. She came to me with diarrhea. She did not have it previously. I was told to mix her old food with the new food 50/50. She was on diamond naturals adult food. I wasn't thinking and put her on 50% diamond and a mix of rachel ray nutrish and purina naturals. Gave her fancy feast tuna. (Ok. I now know this was stupid. Forgot I had to give her kitten food. ). She loves to eat and drink but the diarrhea continues. I took a sample of her diarrhea for evaluation and there was no parasites. I have been feeding her blue buffalo kitten only. The problem is that she will sneak the adult cats food. She looks great and has gained 2 pounds in the last 8 weeks. However, she still has the "cow patties " for stools. Any advice on what food to switch her to? Also should I switch gradually or just at once as she does have the cow patty stools. Thank you.