We seek to evaluate whether a same day, reduced liquid volume (2liters) polyethylene glycol (PEG-ELS) bowel preparation can achieve adequate colon cleansing in patients scheduled for afternoon colonoscopies. The primary outcome will be adequacy of the bowel preparation. Secondary outcomes will include Boston Bowel Preparation Scale score, patient compliance with completing the preparation, tolerability of the preparation, willingness to repeat the preparation, side effects, duration of procedure (endoscope insertion and withdrawal times), and polyp detection.