Our 10 Year Old Son Doesn't Clean Himself Properly After

Our 10 year old son doesn't clean himself properly after a bowel movement. We find bits of poop in the tub, in the sink, on his towel, on the vanity, etc. This started after we told him we were moving to another state in less than two years. The issue started not long after we told him about the move. Now it has been going on, off and on, for the last 6 months. We have tried to talk to him about it. He says it is an accident and that he is not doing it on purpose, but this is hard to believe since he did not have this issue when he was younger. He has been potty trained since he was 2 and has never had any issues before 6 months ago.