Plenty of jokes begin with the phrase, "If men had periods." (They'd brag about the size of their tampons, or they'd check into the hospital once a month for a morphine drip.) This video from BuzzFeed shows what actually happens when three men get a visit from Aunt Flo.
OK, technically they're rigged up to a contraption that releases a steady flow of a blood-like substance. But over the course of three days, they learn that even without hormones and cramps, a period is a hell of a lot to handle.