Randomized Trial Comparing Carbonated Drink With Water as a Solvent for Colonoscopy Solution

90ml of sodium phosphate will be added to 800ml of solvent( water or zero calorie carbonated drink) and taken in divided doses one day prior to procedure. Whole solution will be finished 3 -4 hours before colonoscopy.

800 ml of water will be added to 90 ml of sodium phosphate to facilitate its intake by the patients preparatory to colonoscopy

800 ml of zero calorie diet cola will be added to 90 ml of sodium phosphate to facilitate its intake by the patients preparatory to colonoscopy