Someone mentioned tough love, and I too am on that agreement. My daughter was 3 1/2 before she stayed clean/dry. She could use the potty, and knew how it was more a matter of wills. Its the only thing really that they [ the child] have control over. You cannot MAKE THEM use the bathroom, and they know it. But making them accept responsibility is the route to go. If he messes his pants, hand him some clean underwear/pants etc.. and escort him to the bathroom and hand him the box of wipes and tell him he needs to remove the messy pants himself, and clean his own butt. Sometimes a little poop on the hand [ his not yours] cures this. He may cry, and refuse, but you also can refuse to clean him. I even went as far as to put my daughter in the tub and using mildly warm/cooler then normal water, "hosed" her off like I would the dog. I also made it a rule, if you have messy or wet clothes you are not allowed to sit on the furnature, but a towel on the floor. It seems cruel, but unless there is a specific reason why he is not capable of training, he should be able to atleast use the potty and make every attempt to wipe/clean himself. They do not do a good job of course, so you still have the streaks, but atleast he is accountable for his actions. As for school.. is the policy that they cannot come until fully trained, or do they work with the child provided you send spare clothes? I would take him the first day in underwear and with a change of clothes.