Sounds like it is not the food. Possibly he could have ate something else that isnt agreeing with him, or maybe he is just sick. Is he up to date on his shots??Against Parvo???
Make sure he still drinks and doesnt get dehydrated, and since it has been a few days already, if he is still like this tomorrow, Id get him to a vet!!! Diarrea can lead to dehydration very fast, and that can lead to death.
Tonite, if you hav esome, dilute 1 tbs of pepto with 1/2 water, and give him about 1 tbs of the mixture to see if it helps.
If it was my dog, I'd have already been at the vet. Is it possible he ate a toy, pieces of rope ~ anything that could cause an obstruction? Your feeding your dog a good food, and I wouldn't worry it had anything to do with that, more less what else it got a hold of, or what else could be causing the not eating.
Sorry to hear that.........I agree with everyone else take your dog to the Vet before he? dehydrates..............It could be a number of things that is causing it..giardia, blockages etc...The Vet is best equipt to solve this problem