Lactulose vs. Polyethylene Glycol as Bowel Preparation for Colonoscopy in Adults

4 tablets of Bisacodyl (5 mg) + 250 mL (162.5g lactulose) of lactulose + 600 mL of water + 2 L of water

4 tablets of Bisacodyl (5 mg) + 3 bottles Polyethylene Glycol 3350 (Polyethylene glycol 3350 60 g; sodium chloride 1.46 g; potassium chloride 745 mg; Sodium bicarbonate 1.68 g; anhydrous sodium sulfate 5.68 g; pineapple flavoring 483 mg) + 3 L of water