Each patient would be randomised to receive one of the three colon cleansing agents (Sodium Phosphate, Sodium Picosulphate or PEG) that are routinely used in clinical practice. The endoscopy administration staff at each site would be responsible for random allocation of the bowel preparation using random number generation with the resultant bowel preparation being collected by the patient from a pharmacy, as per usual practice, prior to the colonoscopy. There are no exclusion criteria for bowel preparation selection.