Jackson seems to do the same thing. Usually, he will spit out what is not good for him though. Minus his poop eating problem.
Everytime I see him out back, he's got some stick in his mouth, some poop, or something else. I try to stop it as much as possible, but he's never really had tummy issues except one time but he began feeling better the next morning. I figure he's a dog, and dogs will be dogs. Usually he is smart enough to spit out the bad stuff. I caught him the other day running around with a lizard! One day he brought in a dead mouse to me, all proud. Gross.