Objectives:Current bowel preparation scales (BPSs) have significant limitations including an inability to distinguish among bowel preparations that adequately cleanse a high percentage of colons. We assessed the reliability and validity of the new Chicago BPS and compared it with existing BPSs.Methods:We performed a prospective evaluation of the cleanliness of 150 colons. Inter-rater agreement was assessed using kappa and Pearson correlation coefficients. Each colon was rated by a gastroenterologist and physician's assistant using the Ottawa BPS, the Boston BPS, a dichotomous (adequate/inadequate) BPS (where adequate was defined as being able to visualize at least 95% of the mucosa), and the Chicago BPS.Results:Pearson correlation coefficients between the gastroenterologists and physician's assistant for total BPS scores were 0.79 (95% confidence interval (CI): 0.73, 0.85), 0.79 (95% CI: 0.72, 0.84), and 0.84 (95% CI: 0.79, 0.88) for the Ottawa, Boston, and Chicago BPSs, respectively. Kappa coefficients for right, middle, and distal colon segment ratings were 0.66, 0.53, and 0.49, respectively, for the Ottawa BPS; 0.64, 0.66, and 0.54, respectively, for the Boston BPS; and 0.70, 0.62, and 0.63, respectively, for the Chicago BPS. Differences between the Chicago BPS and the other BPSs were not statistically significant. The Chicago BPS exhibited the best correspondence between BPS total score and the adequate/inadequate BPS.Conclusions:This study demonstrated the validity and reliability of the Chicago BPS. The better defined grading criteria, better designed numerical ratings scale, and better correspondence between Chicago BPS total score and the adequate/inadequate BPS make the Chicago BPS an attractive alternative to the Ottawa BPS and the Boston BPS.

OBJECTIVES: We assessed the safety, efficacy, and tolerability of a new preparation of Gatorade and polyethylene glycol (PEG) for colonoscopy with or without bisacodyl compared with NuLYTELY. METHODS: We performed an investigator-blinded, placebo-controlled, randomized trial of 64 oz of Gatorade and 306 g of PEG (G/PEG) with or without 10 mg of bisacodyl and NuLYTELY. A total of 600 outpatients consumed their preparation the day before a morning colonoscopy. The primary endpoint was colon cleanliness assessed by the Boston Bowel Preparation Scale (BBPS). Tolerability was assessed using a subject questionnaire, and safety was assessed from a basic metabolic profile drawn before the colonoscopy. RESULTS: Adding bisacodyl to G/PEG caused more abdominal bloating/cramps ( P <0.01) and did not result in a cleaner colon ( P =0.66) compared with G/PEG without bisacodyl. The BBPS scores in both the G/PEG arms and NuLYTELY arm were not significantly different ( P =0.19). Compared with subjects in the NuLYTELY arm, subjects in the G/PEG without bisacodyl arm had less nausea ( P <0.04), vomiting ( P <0.02), abdominal pain ( P <0.02), bloating ( P <0.005), difficulty drinking the liquid ( P <0.0001), and found the overall preparation easier to tolerate ( P <0.0001). Subjects in the combined G/PEG arms had a lower serum sodium ( P <0.0007), chloride ( P <0.007), and BUN ( P <0.0001) levels than those in the NuLYTELY arm, but this did not cause any clinical symptoms. CONCLUSIONS: Bisacodyl added to G/PEG for colon lavage caused more side effects and did not result in a cleaner colon. The G/PEG preparations cleansed the colon as well as NuLYTELY, were far better tolerated, and were equally safe.

The cleanliness of the colons was not significantly different among the 3 split-dose preparations. Day-prior dosing of Gatorade and 357 g of PEG allowed the mucosa to be visualized as well as did the split-dose preparations.