Jennifer, I think you're right. You need to get some firm answers! Did they not ask for a stool sample before??? Did they do any blood work? I have to go back and re-read your original post. Was it Flagyl (metronidazole) that he was on??? I know how this is stressing you. When something's wrong, but you don't know what or why, it's on your mind constantly. Do you have faith in your vet? If you don't get the answers you need, perhaps you could see another? I feel so badly for Duncan and you too! Let us know what you decide. We're thinking of you, and send love and hugs to Duncan! Sandra, Star and Cody