R.
Remember to take him at times when you go so he sees/hears
mommy go. And have daddy do the same.....find a target
to put in and tell him you have to aim for the target.
*colored toilet paper or draw on it with a target *.
It will help to have role model for standing up and aiming.
Sounds like his going poo in the toilet is a good start...reward him with praise...it will move to pee stage
soon.