Randomized Trial of Gatorade/Polyethylene Glycol With or Without Bisacodyl and NuLYTELY for Colonoscopy Preparation

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.