Background and study aim: Effective colonoscopy depends on adequate visualization of the intestine, which might be ensured by intraprocedural use of a cleansing device.We investigated the performance of a novel endoscopic device with regard to cleanliness, safety, and tolerability during colonoscopy, compared with standard cleansing. Patients and methods: At a single center, colonoscopy patients in whom the cecum was accessed and at least one bowel segment was inadequately cleansed were assigned to either use of a disposable catheter cleansing device (JetPrep), used through the endoscope working channel, or standard manual cleansing using a 50-ml syringe. The cleansing quality, for each segment and before and after irrigation, was recorded using a 4- point scale ranging from excellent (grade 1, no more than small bits of adherent feces) to poor (grade 4, large amount of fecal residue). Results: 38 patients were included, 19 in each group.Reasons for referral included colorectal cancer screening (52 %), or blood loss (31 %). Each segment showed improvement after cleansing with JetPrep.Overall cleansing grade improved by a mean of 0.74 points (standard deviation [SD] 0.82) in the investigation group compared with 0.19 (0.40) in the control group (P<0.0001), and right colon cleansing improved by 1.59 points (0.71) versus 0.31 (0.48) in the controls (P< 0.0001). There was no significant difference in procedure time between the groups. No adverse events or side effects were encountered. Conclusions: The JetPrep disposable catheter device is safe and efficient for intraprocedural cleansing of a suboptimally prepared colon, allowing higher quality colonoscopy.