The Factors Affecting Proximal Colon Cleansing Based on Bowel Kinetics: Prospective Observation Study

Abstract

Introduction: Inadequate bowel preparation is a major impediment to the effectiveness of colonoscopy. Several recent studies suggested that colonoscopy is less effective in the proximal compared with the distal colon because of relatively poor bowel preparation. There are few studies related to bowel movement after PEG administration about colon cleansing quality. This prospective observation study investigated whether first defecation time after PEG administration affects cleansing quality in the proximal colon. Methods: We prospectively enrolled 425 adults 20 to 75 years of age undergoing colonoscopy for screening at the Comprehensive Medical Examination Center of the St Vincent Hospital between April 2015 and March 2016. Bowel cleansing was accomplished by taking 4L of polyethylene glycol. Surveys including first defecation time were conducted. Endoscopists recorded the quality of bowel preparation at each segments (Rex DK et al. AJG 2006;101:873-885). Results: A total of 425 consecutive eligible patients were investigated. The average ‘first defecation time' after ingestion of PEG was 54.35 minutes. The quality of bowel preparation in the proximal colon was relatively inadequate compared to that of the distal colon. The adequate(excellent, good) bowel preparation group in the proximal colon vs The inadequate(fair, poor) group was 360(84.7%) vs 65(15.3%). Multivariate analysis showed that female gender(P=0.029), thin waist circumference(P=0.027) and long ‘First defecation time'(P=0.034) were associated with inadequate bowel preparation in the proximal colon. Conclusion: Our date demonstrate that ‘first defecation time', female gender and thin waist circumference affect the preparation quality in the proximal colon. Inadequate preparation in right side colon is more common in women. Slow bowel movement kinetics and thin waist could make the quality of the proximal colon inadequate and increase the miss rate of the proximal colon.