I don't understand what you mean when you say you want to 'stop it'. Stop what? If you hear him cry, have him use the potty. You have observed the pattern - now all you have to do is respond to it.
Hello anniebee, I am studing to be a kindergarten and I know that for children it is very difficult to control their poop. Going to the toilet is a process difficult to assimilate.
Maybe, he cries because you punished him before, and now he is scared about it. Talk to him, tell him that nothing is gonna happen, that is natural. You have to check his medical condition, too. Maybe something is hurting his anos or he´s got a orinal infection.
I hope my answer can help you. By the way, always check everything with a doctor, or psycologist.
That doesn't help me. WHAT DO I DO TO STOP IT?????????
If you know that he has to use the potty, let him use it. Spanking him is really wrong - he is not doing anything wrong. As ana side, even if he was doing something wrong, spanking him is not useful.