
I've just had my dog Daisy at the vets for just this very thing, I don't know if the technical term would be gastric reflux, but that's how I described it to my vet and he knew exactly what I was on about.
Daisy's problem is she only eats once a day ( her choice ) having an empty stomach makes her bring up yellow bile, sometimes she will bring it up, only to swallow it again.
All fixed now though with Famotidine tablets, which have worked very quickly.
My vet also mentioned that feeding protein with cheese was very effective and long lasting.