4yo used to be able to wake up when needing to pee, but reverted to wetting the bed

So, a month ago or two, my 4yo would routinely wake up at 10-11 pm, and use the toilet. But for some reason, he stopped doing that and I have to change the sheets almost daily again.What happened? What can I do? Obviously being physically able is not the problem. via /r/Parenting http://ift.tt/2gFrax2