TWO LITERS OF POLYETHYLENE GLYCOL (PEG) WITH 15 MG OF BISACODYL VERSUS 4 LITERS OF PEG FOR BOWEL PREPARATION TO COLONOSCOPY - Elmekkaoui, A; Oualgouh, M; Zazour, A; Khannoussi, W; Kharrasse, G; Ismaili, Z (Endoscopy, 2018)