My 8 Year Old Pom Had Bloody Diarrhea And Was

My 8 year old pom had bloody diarrhea and was vomiting earlier today. I took him to the vet and the vet said he didn't find anything but to bring a stool samle backhe gave my dog a Maropitant injection and Metronidazole tablets.my dog has been tired and laying around all day.He will fall asleep and each time he keeps twitching and snoring and breathing slow then fast.he usually does snore and make noises when he sleeps but I am worried about him because he is still acting so tired and just laying around.Should I take him to a 24 hour emergency vet ?