Preparation before colonoscopy: a randomized controlled trial comparing different regimes

Background and aim A good bowel preparation is essential for optimal visualization of the large intestine. Several preparations with a difference in composition and volume are available. We compared five methods for bowel cleansing quality and patients' acceptability. Patients and methods Adult ambulatory outpatients scheduled for elective colonoscopy were randomized to receive 4-I polyethylene glycol (PEG) solution (Klean-prep), 2-I PEG solution + ascorbic acid (Moviprep), or a sodium phosphate (NaP) solution, Phosphoral. Patients with the PEG solutions were also randomized to receive simethicone (Aeropax), to investigate whether this improves the bowel cleansing efficacy. Before colonoscopy patients completed a questionnaire about the acceptability and tolerability of the preparation. Endoscopists blinded to the type of preparation gave a bowel cleansing score. Results Data were available for 461 patients. 2-I PEG + ascorbic acid was noninferior to 4-I PEG in bowel cleansing quality of rectosigmoid and colon. NaP was noninferior to 4-I PEG in bowel cleansing quality of rectosigmoid but inferior for the whole colon. Compliance was significantly less in the group with 4-I PEG compared with the 2-I PEG and NaP group. No difference was found for abdominal cramps. Taste was significantly better in the 2-I PEG group. Simethicone did not improve the bowel cleansing quality. Conclusion 2-I PEG + ascorbic acid was noninferior to the 4-I PEG solution in bowel cleansing quality and was better in taste and compliance. NaP was inferior to 4-I PEG in bowel cleansing quality. Addition of simethicone gave no improvement. Eur J Gastroenterol Hepatol 23:897-902 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.