I often think that 2 is too young for children to be completely dry I know other countries start young however sometimes if they are not ready they regress, he will get back to it, is he sore, chapped
in any way as bath water may sting ,check for redness, has anything new happened
in his life , day care a new sibling, family visiting, children are creatures of habit, if there is something new happening he may feel vunerable.