Pooping by myself

Once at Grandma and Grandpa's house, and once here, Sharon and I have been about to go to bed only to discover poop in the little frog potty. Usually Enoch just pees in there and poops on the big toilet, and then we wipe his bottom. So it was no surprise when we checked on him, he was sleeping peacefully like he always does, but when we pulled down his pants there was poop everywhere. The next day he had little recollection of any of it, although he did seem slightly embarrassed. Poor guy just gets so tired and doesn't know what to do.