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Canadian Journal of Gastroenterology
Volume 20, Issue 11, Pages 699-710
Special Article

Commonly Used Preparations for Colonoscopy: Efficacy, Tolerability and Safety – A Canadian Association of Gastroenterology Position Paper

Alan Barkun,1,2 Naoki Chiba,3,4 Robert Enns,5 Margaret Marcon,6 Susan Natsheh,7 Co Pham,8 Dan Sadowski,9 and Stephen Vanner10

1Division of Gastroenterology, McGill University Health Centre, Canada
2Department of Clinical Epidemiology, McGill University, Montreal, Quebec, Canada
3Division of Gastroenterology, McMaster University, Hamilton, Ontario, Canada
4Surrey GI Research Inc, Guelph, Ontario, Canada
5Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
6Division of Gastroenterology, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
7Department of Pediatrics, Saint John Regional Hospital, Saint John, New Brunswick, Canada
8Faculty of Pharmacy, McGill University Health Centre, University of Montreal, Montreal, Quebec, Canada
9Division of Gastroenterology, Royal Alexandra Hospital, Edmonton, Alberta, Canada
10Hotel Dieu Hospital, Kingston, Ontario, Canada

Received 29 August 2006; Accepted 29 August 2006

Copyright © 2006 Canadian Association of Gastroenterology. This open-access article is distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC) (, which permits reuse, distribution, and reproduction of the article, provided that the original work is properly cited and the reuse is restricted to noncommercial purposes.


INTRODUCTION: The increased demand for colonoscopy, coupled with the introduction of new bowel cleansing preparations and recent caution advisories in Canada, has prompted a review of bowel preparations by the Canadian Association of Gastroenterology.

METHODS: The present review was conducted by the Clinical Affairs group of committees including the endoscopy, hepatobiliary/transplant, liaison, pediatrics, practice affairs and regional representation committees, along with the assistance of Canadian experts in the field. An effort was made to systematically assess randomized prospective trials evaluating commonly used bowel cleansing preparations in Canada.

RESULTS: Polyethylene glycol (PEG)-; sodium phosphate (NaP)-; magnesium citrate (Mg-citrate)-; and sodium picosulphate, citric acid and magnesium oxide (PSMC)-containing preparations were reviewed. Regimens of PEG 2 L with bisacodyl (10 mg to 20 mg) or Mg-citrate (296 mL) are as effective as standard PEG 4 L regimens, but are better tolerated. NaP preparations appear more effective and better tolerated than standard PEG solutions. PSMC has good efficacy and tolerability but head-to-head trials with NaP solutions remain few, and conclusions equivocal. Adequate hydration during preparation and up to the time of colonoscopy is critical in minimizing side effects and improving bowel cleansing in patients receiving NaP and PSMC preparations. All preparations may cause adverse events, including rare, serious outcomes. NaP should not be used in patients with cardiac or renal dysfunction (PEG solution is preferable in these patients), bowel obstruction or ascites, and caution should be exercised when used in patients with pre-existing electrolyte disturbances, those taking medications that may affect electrolyte levels and elderly or debilitated patients. Health Canada’s recommended NaP dosing for most patients is two 45 mL doses 24 h apart. However, both safety and efficacy data on this dosing schedule are lacking. Many members of the Canadian Association of Gastroenterology expert panel administer both doses within 24 h, as studied in clinical trials, after careful one-on-one discussion of risks and benefits in carefully selected patients. Safety data on PSMC and combination preparations in North America are limited and clinicians are encouraged to keep abreast of developments in this area.

CONCLUSIONS: All four preparations reviewed provided effective bowel cleansing for colonoscopy in the majority of patients, with varying tolerability. Adequate hydration is essential in patients receiving the preparations.