he's still young. pooping can be difficult for some kids. some kids feel as if a part of their body is falling away and it can be scary. you just need to give him time. try to notice his cues when he's starting and try to get him on the potty. i bribed my son with baskin robbins. he didn't care at first but once i started ignoring him, he did it all on his own and i rushed him to baskin robbins at like 11am! he never had another accident after that. be patient.