D.D.
I think that the key element is to "stay positive". Potty training with my son was a very long and difficult process, until I realized the more positive I was about the entire thing the better he got at it. At 3 years old he has little control over much of his life and "potty control" is one thing that only he can control. Children do view their #2 as an extension of their body and for some kids it is not easy to let go. I think he needs to be comfortable. The previous poster who suggested that he stand in the bathroom or sit on the potty with the pull up on was a great idea. It gets the child comfortable with being in the bathroom to do the #2. He will get there, it is a control issue some what, just stay positive and it will happen.
Good Luck