How long does it take for Prune juice to clear up my constipation?

I just drank 2 warm cups of prune juice to clear out my weird bowel movements and get back to regular. Its not too severe as I can get a little out but theres some thats just...not wanting to work with me! Haha I want to know if I should just go to sleep, or wait till I start shittin myself silly. (I mixed in some miralax.)