
Originally Posted by
Mercen-X
Your body doesn't wake you up. You dream about toilets or swimming pools and about being a little little kid. Only if you have will power enough to realize you're dreaming and wake up can you avoid relieving yourself while you sleep. I'm very good at this unless I haven't gone all day, then I make sure to take a trip before I sleep.
If you haven't gone all day, then you're using your muscles to avoid going, and thus if you fall asleep, your muscles will relax and you'll go.