Ok, so I've got this categorized under jokes, although it seems believable enough to me.  Young guys, screwing around, looking for some pain relief and ending up with an unexpected colon cleanse!!  You can read the whole thing here, probably will take about 5 minutes or so.  Basically, this guy has trouble with number two for a few days, then grabs some ex-lax, but instead of following the recommended dosage, takes WAY too much.  The rest of the story is pretty much his friend making fun of him.  Ahh, the perils of being twenty something.