My 3 yo son has been potty trained for about a year. Over that year he has averaged pee accidents about 10% of the time. Not a huge deal, but it seems like he should be able to control this. I haven't done much about it except firmly reinforcing the expectations when I find him wet. Over the past week or so he has starting to poop in his pants about 50% of the time. Today he pooped in his pants at preschool. What's the best approach for regression at this age.