An Investigator-Blinded Randomized Controlled Prospective Study Comparing Efficacy, Tolerability, and Safety of Two Bowel Preparations in the Community Setting: Miralax Versus PEG Electrolyte Lavage Solution (PEG-ELS)

Abstract

Introduction: Although not FDA approved, Miralax (PEG 3350) mixed with Gatorade is a frequently used colonoscopy bowel preparation. There is conflicting data regarding its efficacy and tolerability, and limited data on its safety. We aimed to compare the efficacy, tolerability and safety of Miralax with Gatorade and PEG-ELS (polyethylene glycol electrolyte lavage solution) in the community setting. Methods: Patients undergoing elective screening colonoscopy were randomized to receive either splitdosed Miralax or PEG-ELS. Serum electrolytes, calcium, and phosphorus were determined before and after the preparation. Patients completed a Likert scaled questionnaire (1 = strongly agree; 5 = strongly disagree) evaluating their experience with the preparation just before colonoscopy. Quality of preparation was scored by blinded endoscopists using the Boston Bowel Preparation Scale (BBPS). Results: Sixty seven patients received either Miralax (N=38) or PEG-ELS (N=29). The groups were comparable regarding age, sex, and race.There was no significant difference in efficacy between the Miralax and PEG-ELS groups, with mean total BBPS scores of 7.34 and 7.82, respectively (p=.153). There was no significant difference in the ability to complete at least 75% of the preparation between the groups, but more patients were willing to retake (29.1 vs 40.4; p=.008) and/or recommend (28.5 vs 41.1; p=.003) their Miralax preparation in the future. The Miralax group also found the amount of preparation (27.9 vs 41.9, p=.001) and its taste (26.3 vs 44, p < .001) more acceptable and their preparation to be more tolerable (27.4 vs 42.6, p < .001). The Miralax group experienced less headache than the PEG-ELS group (29.2 vs 40.1, p=.003) but there was otherwise no significant difference in side effects. Finally, there was no significant difference in serum electrolytes before and after taking the preparations in either group. Conclusion: Both split-dosed preparations are effective at colon cleansing without adverse changes in serum electrolytes. However, patients in the Miralax group found their preparation to be more tolerable than those in the PEG-ELS group. Additionally, more patients were in favor of using or recommending Miralax again in the future. This study adds to the growing body of data regarding bowel preparation regimens and supports the effectiveness and safety of Miralax in preparing the bowel for colonoscopy with improved patient acceptance and tolerability.