Picture this: You're a regular once-a-day pooper (or even twice a day, if you're feeling productive). And yet every time you leave home for an extended period of time, you find yourself completely unable to go to the bathroom. One day passes, then two, then three, then four. Pretty soon, instead of enjoying your long-awaited beach vacation, all you can think about is whether you'll ever have a bowel movement again. Your life stretches before you like a bleak, poop-less tundra.