2 L versus 4 L of PEG3350+electrolytes for outpatient colonic preparation: a randomized, controlled trial

Background: Low-volume bowel preparations are ideal to ensure patient compliance, thus enabling high-quality examinations to be achieved. Objectives: To examine the bowel-cleansing efficacy and patient tolerability of split-dose 2 L PEG3350 + electrolytes (PEG3350e) with 15 mg bisacodyl versus split-dose 4 L PEG3350e. Design: Single-blinded, noninferiority, randomized, controlled trial. Setting: Single site, university-affiliated tertiary care center. Patients: A total of 325 consecutive patients undergoing elective outpatient colonoscopy. Intervention: 2 L of PEG3350e with 15 mg bisacodyl versus 4 L of PEG3350e, both given in a split-dose fashion. Main Outcome Measurements: Efficacy and tolerability of a split dose of 2 L of PEG3350e with 15 mg bisacodyl. Efficacy was assessed by using the Boston Bowel Preparation Scale and Ottawa Bowel Preparation Scale. Patient satisfaction and tolerability were assessed by using a short survey. Results: A total of 325 patients were included in the intention-to-treat analysis (51% male) with a mean +/- standard deviation age of 56 +/- 11.2 years. No statistically significant difference in cleanliness was found by using the Boston Bowel Preparation Scale (intention-to-treat, P = .381; per-protocol, P = .387) and the Ottawa Bowel Preparation Scale (intention-to-treat, P = .285; per-protocol, P = .334). Participants receiving 2 L of PEG3350e found the preparation easy to consume and were willing to repeat the procedure more often than the 4-L group (P < .001). Limitations: Single-center study looking at outpatient colonoscopies; unable to comment on adenoma detection rate. Conclusions: Bowel-cleansing efficacy was similar in both the 2-L and 4-L PEG3350e groups; however, patient tolerability and willingness to repeat preparation were statistically greater with the 2 L of PEG3350e with 15 mg bisacodyl regimen.