everytime i open a webpage, i see this ad and just start to think about it.. it's been on talkshows and news casts... but my sister in law is a nurse in the endoscopy unit at the hospital and advised me it's not good for you- you should only cleanse your colon about once a year.  has this diet been on the doctors? does it reaaally work? ..someone with real answers and real adivce, please help.