Getting 'cleaned out' before L&D?

Is it true that your body can start clearing itself out before labor? I haven't been able to leave the bathroom since last night. I'm not really in any pain, my stomach isn't hurting until right when I'll need to go. But I've had horrible diarrhea like 7 times. Could this be my body getting itself ready? It didn't happen with my first son but I've read it can definitely be a thing so did it happen for you?