597 Background: Though numerous researches enabled decrease of the bowel preparation solution volume, it is still a major complaint of patients preparing colonoscopy. There have been studied that additional administration of laxatives could lessen the amount of aqueous formula with prokinetic effect. Prucalopride is a serotonin (5-HT4) receptor agonist which stimulate colonic mass movements and provide main propulsive force for defecation. The aim of this study is to compare 2-L PEG-Asc and 1-L PEG-Asc plus prucalopride for quality of bowel cleansing while preparing for colonoscopy and patient compliance. Methods: Two hundred patients were prospectively enrolled. Patients referred for colonoscopy were divided into group A (the split-dose 2-L PEG-Asc) and group B (1-L PEG-Asc + prucalopride) randomly. During colonoscopy, each patient’s bowel preparation quality was evaluated with The Boston Bowel Preparation Scale (BBPS) and Aronchick Preparation Scale (APS). The tolerability and satisfaction of patients was determined based on a questionnaire-based survey. Results: One hundred patients received either 2-L PEG-Asc or 1-L PEG-Asc with prucalopride. Regarding colon cleansing outcome (BPPS and APS), the 1-L PEG-Asc with prucalopride group showed similar, but non-inferior results compared to the 2-L PEG-Asc group on both BBPS (7.65±1.27 vs 7.52±1.40, p = 0.586) and APS scales (93.3% vs 95%, p = 0.717). Tolerability was similar for both 1-L PEG-Asc with prucalopride and 2-L PEG-Asc. Conclusions: 1-L PEG-Asc plus prucalopride preparation showed comparable result to traditional 2-L PEG-Asc preparation. 1-L PEG-Asc plus prucalopride preparation method could be an alternative method for bowel preparation which can relieve patient’s discomfort. Clinical trial information: KCT0002409.