My husband is getting a colonoscopy next month. His doctor gave him instructions to prepare and I wanted to know if this common. 5 days before the procedure he starts taking Milk of Magnesia morning and night. He takes this on day 5, 4 and 3. On day 3 he adds taking Dulcolax or Mirolax with a sports drink. Day 2 he just takes the Dulcolax and only has clear liquids. Can't he just do a purge the day before? Seems likes this will be very uncomfortable for all 5 days.