W.B.
My son Owen was not completelty potty-trained until he was 3 and a half. A potty chart worked best for us. We made one up on our own. It had 12 squares that he got to put a sticker on each time he went in the potty. For poop, he got to put a Superman sticker, which was "better" than the other stickers. Everytime he filled the chart with stickers, all 12 squares, he got a (reasonable) prize that he got to pick out.
Hope this helps!