Objective To explore the effects of using different dosing regimens during bowel preparation for colonoscopy performed in the next morning in endoscopic day ward.

Methods A prospective, single blind, randomized, single center study was conducted, including 141 patients who were admitted to the endoscopy day ward of Zhongshan Hospital, Fudan University from November 2018 to February 2019 for colonoscopy diagnosis and treatment in the morning of the next day. The patients were divided into intervention group (69 cases) and control group (72 cases). In the intervention group, 2 times of drug administration plan was used for intestinal preparation, while in the control group, 1 time of drug administration plan was used. The difference of the bowel preparation quality (qualified rate based on BBPS) and patients' symptoms (nausea, vomiting, etc.) were compared between the two groups.

Results In patients who were given a split-dose regimen of lustramentum had a significantly higher qualified rate than those who were given a single dose regimen (87.0% vs 65.3%, P=0.003). Patients in the intervention group had fewer and milder symptoms (P < 0.05).

Conclusions Split-dose regimen can be used as a standard protocol of bowel preparation for patients who will receive colonoscopy in the next morning in endoscopic day ward.