some dogs just like eating poop. Labrador Retrievers are notorious for it. Changing your dog's food may help, so can using food additives like "Deter". You can get them from your local pet supply store. Your best bet to stop him is to keep him on a leash, so after he poops you can direct him elsewhere before he has a chance to turn around and eat it. You can also correct him when he makes the attempt with a leash jerk and a sharp word.
Never trust a tall dwarf... he's lying about something.
I am taking care of a Shih Tzu puppy I bought my mom and she eats her own poop. I asked our vet about it and he said it is not uncommon. When I take her outside to potty on the leash, after she poops I direct her away from it. But she has accidents in the house that I don't see right away and boom she has it. I'm hoping in time she will stop doing that. It's gross and I really don't want her little kisses after she's done it, YUCK!