[Ellie May]

When was his food switched?
What was the quarantine process/inspection process? Was he away from you at all? How many days ago did he fly?

I would go with the chicken and rice and then slowly transition to his old food if he did well on it. As Wylie's Mom said, appetite is a good sign. Only feed small amounts if he is eating fast though. That could retrigger a problem.

A couple times of vomit or diarrhea generally is no big thing, but if he threw up everywhere and has had diarrhea, it really is best to go to the vet. In the case of a couple issues no food by mouth is the recommendation.