My last girl did this all her life, she had to be put down at age 17 y/o. I worked all day, she was retrained from outside to inside when I moved, commuted 1 1/2 hours to and from work, I was gone 16hours, reason had to retrain to make on paper. So she ate the poop when I was at work. When I was home whether she made in or outside I was there to pick it up. I tried everything that was suggested, nothing worked. My vet said it could be from the poop smelling like her food. At that time I never heard about feeding pineapple. Sometimes I catch Cody trying this, I am ALWAYS with in sight when he goes, if I see him turn to smell it I call out to him and pick it up right away. I had a special screen door made years ago with a doggie hatch, in the summer my back door is open so he can go out to make, he is confined to deck only, one day he brings me his poop
, that's how I discovered he was attracted his his poop. Soon after that I did catch him in the act of eating it, so he is watched very carefully, and I pick it up just as it hits the ground. Good luck, I hope you can resolve this nasty habit, if he continues to do this, that is just what it will become...a habit that will not be easy to stop.