Laxatives help empty the bowels so a doctor can examine the colon thoroughly This procedure is done using a long, flexible tube (a "scope") that passes into your rectum and through your colon 6 hours before the test is scheduled, finish drinking the rest of the Miralax mixture over a period of ½-1 hours Take 2 Dulcolax (or generic brand bisacodyl) pills with a full glass of water 2 Please avoid red Jell-O and all milk products, however