Randomized, Controlled Trial of the Use of Magnesium Citrate with Polyethylene Glycol Electrolyte Lavage Solution for Morning Colonoscopy Preparation

Abstract

Introduction: Large volume of polyethylene glycol electrolyte lavage solution (PEG-ELS) for bowel preparation before colonoscopy reduces patient's tolerance and increase sleep disturbance in the patients undergoing morning colonoscopy. The aim of this study was to compare the tolerability and efficacy of three bowel preparation methods for morning colonoscopy: 4L of PEG-ELS; split-dose of PEG-ELS; and magnesium citrate plus 2L of PEG-ELS. Aims and Methods: This was a randomized, single-blinded, controlled study. Total 232 consecutive patients scheduled for outpatient elective colonoscopy were prospectively and randomly assigned to one of three preparations(Group 1(n=79): 4L of PEG-ELS at 10PM; Group 2(n=80): 2L of PEG-ELS at 8PM on the preceding day and 2L at 5AM on the day of colonoscopy; Group 3(n=73): magnesium citrate(250cc) at 8 PM on the preceding day and 2L of PEG-ELS at 5AM on the day of colonoscopy). Endoscopists were blinded to the types of preparation. The quality of bowel cleansing was rated using Aronchick scale (excellent, good, fair, poor, inadequate) and Ottawa scale. Tolerability and adverse effects of assigned preparation were evaluated by questionnaire completed by each patient before the procedure. Results: There were no differences in compliance and sleep disturbance among three groups (p=0.504, p=0.733). And compared with previous exam, the difference of sleep disturbance was not statistically significant (p=0.075). But, the frequencies of nausea and abdominal distension were much higher in Group 1 and 2 than Group 3 (p=0.002). The sum of symptom score (range 0-11) was also higher in Group 1 and 2 (p<0.0001). Satisfaction rates according to preparation method were 22.8%, 34.7% and 42.6% in Group 1, 2 and 3, respectively (p=0.004). The willingness to choose the same preparation on the next colonoscopy was 48.1%, 62% and 93.2% (p<0.001). In Aronchick scale, bowel preparation of Group 1 was relatively poorer than Group 2 and 3 (p<0.001). The proportion of fair and poor bowel preparation was 48.1%, 23.8% and 24.7%, respectively. And only in Group 1, 7 patients showed inadequate bowel preparation. In Ottawa scale, Group 1 also showed poorer preparation in right colon preparation (p<0.001). But, there was no difference in Group 2 and Group 3 (p=0.398). Conclusion: Preparatory split-dosed magnesium citrate plus 2L of PEG-ELS achieved the lowest symptom score and the highest satisfaction rate. In addition, bowel cleansing effect was superior to single-dosed 4L of PEG-ELS group and similar to split-dosed 4L of PEG-ELS group in morning colonoscopy.