Dharma does this and I have been unable to break her of it. I have tried pineapple in her food and meat tenderizer. The only thing I haven't tried is the Forbid. They are tablets you can buy especially for this but I found them to be quite expensive for the amount you have to give.
I finally have just resolved myself to trying to pick it up immediately before she gets to it. The time this is the hardest is at the Dog Park when she goes on the other side of the park and sometimes before I get to it she has already started to dig in. Then trying to get it away from her becomes a game of keep way!
My dog has/had the same problem. Tried all the standard remedies and products without success. So, for THIS dog I now have a poop-free yard. The only thing that has worked for me is walking her in the woods because, for some reason, she poops and walks away there. Sometimes I think she is doing it to be a brat because if she goes after anything I don't want her to have she will keep going back as a catch-me game. So I may have inadvertently extended the poop-eating problem. Some dogs do this for a life time and it doesn't harm them, it is simply GROSS. One other thing, if she poops while on a leash walk I am always prepared to pull her away and even step on the leash to keep her away while I do the pick-up. Good Luck !!!!