Predictive factors for inadequate colon preparation before colonoscopy

Background It could be helpful to ascertain which patients are at risk of poor bowel preparation prior to performing sedated colonoscopy. The aim of the present study was to identify the predictive factors for poor colon preparation prior to colonoscopy. Methods A prospective study was performed at Kaohsiung Chang Gung Memorial Hospital, Taiwan, from September 2011 to May 2013. Patient characteristics, food consumed within 2 days of colonoscopy, volume of polyethylene glycol (PEG) solution, interval between completing PEG and examination, number of bowel movements, and character of the last stool were evaluated. Results Seven hundred and three patients were enrolled (mean age 50.3 +/- 11.6 years, 43 % female). In univariate analysis, character of the last stool (< 0.001), body weight (p = 0.007), body mass index (p = 0.047), waist circumference (p = 0.008), buttock girth (p = 0.016), meal residue score (< 0.001), and interval between end of PEG and colonoscopy (p = 0.01) were related to inadequate colon preparation. In multivariate analysis, waist circumference (p< 0.001), meal residue score (p< 0.001), and characteristics of last stool (p< 0.001) were variables that predicted poor colon preparation. Conclusions Patients who have consumed a high residue diet and/or who report that their last stool is semisolid are likely to have poor bowel preparation, and consideration could be given to rescheduling the examination.