Have you tried a poop chart or something. That is what we did with ds and within one week, he was totally potty trained. We made a chart and got cool stickers. Each time he went pee, he got one sticker, two for poop. After 5 stickers, he got a small treat, candy or more stickers to play with. The more stickers the more incentives, until he filled up the whole chart for a brand new sand box. He was so enthusiastic about putting the stickers on the chart and earning his sand box.
Of course, I would only award stickers for pooping on the pot in your situation.