R.W.
My son took forever to even pee pee. He is about to be three this week. I wanted him to start prep school, but he had to be potty trained. I asked if there was anything I could do to speed it along. They let him enter the class as long as he had pull ups. By day three, seeing all the other little boys going poo poo, he wanted to do it too. That's all it took. He got it down pat after just two weeks of potty time. I still put a diaper at night time to be safe, we have had a few little wettings, but he is great about going by himself now. He wipes with his kid wipes and all. Washes hands and everything!
So maybe have him go poo poo with daddy. I know it sounds gross, but if he sees another boy doing it, it may help.