Citrus reticulata peel improves patient tolerance of low-volume polyethylene glycol for colonoscopy preparation

Background: Adequate adjuncts help to reduce the volume of polyethylene glycol-electrolyte lavage solution (PEG-ELS) needed, to ameliorate patient discomfort, and to improve colonic visibility during colonoscopy. This study aimed to assess the effect of Citrus reticulata peel (CRP) as an adjunct to low-volume PEG for colonic preparation. Methods: A total of 1092 health examination examinees received colonoscopy during the study period. After excluding those who refused to participate and those who did not meet our criteria, 212 examinees were enrolled into this study. They were divided into the PEG group and the PEG + CRP group according to their date of examination. All examinees received 2 L of PEG-ELS one day before colonoscopy. The PEG + CRP group also received additional CRP in the form of a “buccal tablet” between drinks. Tolerance and adverse events were assessed by questionnaire, while the quality of bowel preparation for colonoscopy was scored by an endoscopist. Results: There were 107 examinees in the PEG group and 105 examinees in the PEG + CRP group. The demographic characteristics of the examinees were comparable between these two groups. Examinees in the PEG + CRP group had a trend of better colonic visibility than those in the PEG group (p = 0.056). Moreover, examinees in the PEG + CRP group had higher rate of acceptable taste (p = 0.015) and lower rate of difficulty swallowing (p = 0.001). The incidences of adverse events including vomiting (p = 0.045), bloating (p = 0.035), and difficulty sleeping (p