I am sure it is the food thing, now that you guys mention it. Usually we leave a little food out at night, but there are a few nights that we haven't and those are probably the mornings he has thrown up.
It is foamy and he is totally fine durring the rest of the day.
Thank you!!
I love being able to come here with my questions. We are going to the vet next week, and so I'll ask him if the night snacks don't help.