RÉSUMÉ
OBJECTIVES@#To investigate the influencing factors for the quality of bowel preparation before colonoscopy in children and the association of the interval from the last administration of laxative to the start of colonoscopy (shortly referred to as waiting time) with the quality of bowel preparation.@*METHODS@#A retrospective analysis was performed for the children who were admitted to the Department of Gastroenterology, Children's Hospital of Nanjing Medical University, from January to November 2020, and received bowel preparation with polyethylene glycol electrolyte powder combined with diet control before colonoscopy. According to the score of Boston bowel preparation scale, they were divided into two groups: adequate bowel preparation group (n=337) and inadequate bowel preparation group (n=30). Related data were collected from the children in both groups, including general information, possible influencing factors for the quality of bowel preparation, adverse reactions associated with bowel preparation, duration of colonoscopy, and postoperative diagnosis. Univariate and multivariate analyses were used to explore the influencing factors for the quality of bowel preparation.@*RESULTS@#The univariate analysis showed that age, body weight, and waiting time were associated with inadequate bowel preparation (P<0.05). The multivariate analysis showed that older age (OR=2.155, 95%CI: 1.087-4.273, P=0.028) and longer waiting time (OR=1.559, 95% CI: 1.191-2.041, P=0.001) were independent risk factors for inadequate bowel preparation. The receiver operating characteristic (ROC) curve analysis showed that the cut-off value of waiting time was 5.5 hours in determining whether bowel preparation was adequate or not, with a sensitivity of 90.0%, a specificity of 50.7%, and an area under the ROC curve of 0.708. After grouping based on waiting time, it was found that the incidence rate of inadequate bowel preparation in the ≥5.5 hours group was significantly higher than that in the <5.5 hours group [14.0% (27/193) vs 1.7% (3/174), P<0.001].@*CONCLUSIONS@#For children who use polyethylene glycol electrolyte powder combined with diet control for bowel preparation, older age is an independent risk factor for inadequate bowel preparation before colonoscopy, which may be associated with an insufficient dose of polyethylene glycol in older children. Longer waiting time is also an independent risk factor for inadequate bowel preparation, and it is recommended that the waiting time should not exceed 5.5 hours.