make him clean himself up after accidents. don't make it a punishment, though. even if he has a fit, stay calm and be soothing and reassuring, eventually, he'll get tired of the mess, and realize that it's easier to go in the potty.
also, what is going on in your son's world right now? Any recent changes or other odd behaviors? Ask him why he won't poop in the potty. Is he afraid of something? If this doesn't work itself out in a few weeks, check with the pediatrician to be sure nothing else is going on.
at 6:47 PM on Nov. 12, 2008