My 6 mth. old mastiff puppy is drooling excessively and has diarreah, is he sick?

I know mastiffs drool a LOT, but he is drooling small puddles. He has had 3 loose stools in the last 24 hours. He is completely vaccinated, and neutered a week ago. His surgery went fine and his incision is not infected, and he is healing on track. He has not had anything out of the ordinary in his diet, that would cause this. he is not acting to be in discomfort, or showing abnormal behaviors.Does anyone have any ideas what it could be, and should I take him to the vet?