bowel preparation
"What a waste of time and money!  Easiest prep I've ever done, but no results for 13 hours after 1st dose, then took 2nd dose 6 hours before procedure and got no more results at all.  Had to cancel procedure.  Took 2 more days to get the Prepopik out of my system!  Now I get to go back and discuss alternative preps and do it all over again."