Purpose: Good bowel preparation is essential for optimal visualisation of the mucosa during colonoscopy. The aim of this retrospective study was to evaluate the efficacy of three types of bowel preparation: Picolax® (sodium picosulphate), single-dose MoviPrep®, and split-dose MoviPrep®. Methods: Two groups of patients—bowel cancer screening and symptomatic patients—who underwent colonoscopy at our institution over a 12-month period were identified. Within the two groups, 50 patients receiving each type of bowel preparation were selected providing a total of 300. Data collected included subjective rating of bowel preparation (good, satisfactory, poor), depth of insertion, timing of endoscopy, and polyp detection. Results: In symptomatic patients, 94% prescribed split-dose MoviPrep® had good or satisfactory bowel preparation with an unadjusted caecal intubation rate of 96%. Eighty percent prescribed single-dose MoviPrep® and 84% prescribed Picolax received the same rating with a caecal intubation rate of 88% and 92%, respectively. More colonoscopies done in the afternoon received a ‘good' bowel preparation rating (65.3% vs 30.8%; p<0.001) and more polyps (52.6% vs 47.4%) were detected regardless of preparation type. MoviPrep® was associated with the highest polyp detection rate (61% vs 34%; p=0.03). In screening patients, 98% prescribed split-dose MoviPrep® had good or satisfactory bowel preparation; 94% prescribed single-dose MoviPrep® and 90% prescribed Picolax® achieved the same rating. There was no significant difference in caecal intubation or polyp detection within the screening group. Conclusion: Split-dose MoviPrep® (low-volume PEG) and colonoscopy performed in the afternoon are two independent factors facilitating better bowel cleansing and higher polyp detection.Figure