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A Trial of Four Different Bowel Cleansing Regimens Prior to Colonoscopy

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00831064
Recruitment Status : Completed
First Posted : January 28, 2009
Last Update Posted : June 13, 2016
Information provided by (Responsible Party):
Dina Kao, University of Alberta

Tracking Information
First Submitted Date  ICMJE January 27, 2009
First Posted Date  ICMJE January 28, 2009
Last Update Posted Date June 13, 2016
Study Start Date  ICMJE September 2007
Actual Primary Completion Date July 2009   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: January 27, 2009)
bowel preparation quality as measured by the Ottawa scale [ Time Frame: at the time of endoscopy ]
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: January 27, 2009)
  • electrolyte and renal function abnormalities [ Time Frame: 2 sets of measurements will be obtained: prior to the start of bowel preparation and at the time of colonoscopy ]
  • patient tolerability of bowel preparation [ Time Frame: at the time of colonoscopy ]
Original Secondary Outcome Measures  ICMJE Same as current
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE A Trial of Four Different Bowel Cleansing Regimens Prior to Colonoscopy
Official Title  ICMJE A Randomized Controlled Trial of Four Different Bowel Cleansing Regimens Prior to Colonoscopy: Efficacy, Patient Tolerability and Safety
Brief Summary To compare 4 commonly used bowel preparations in terms of efficacy, patient tolerability and safety. All these 4 bowel preparations are likely to be efficacious and safe. However, those with lower volume are likely to be better tolerated and completed by patients.
Detailed Description

Adequate bowel preparation is imperative for diagnostic accuracy and therapeutic safety. Several bowel cleansing preparations have been approved by Health Canada and are commonly used prior to colonoscopy. Polyethylene glycol (PEG) has been considered to be the "gold standard" for bowel preparation. It is a nonabsorbable solution which passes through the bowel without net absorption or secretion. Significant fluid and electrolyte shifts are therefore avoided. However, the large volume (4 liters), the salty taste and the sulphur smell frequently lead to poor tolerability and compliance, sometimes resulting in inadequate bowel preparation. Several other bowel cleansing preparations have been developed and include sodium phosphate (NaP), magnesium citrate, and sodium picosulphate plus magnesium oxide (PSMC)-containing preparations. NaP is a low volume hyperosmotic solution which draws plasma water into the bowel lumen to promote colonic cleansing. As a result, significant fluid and electrolyte shifts can occur. The advantage of the low volume is better patient tolerance compared to PEG. However, even in healthy individuals severe electrolyte disturbances have been reported when the 2 required doses are taken 12 hours apart. Therefore Health Canada has recommended that 2 doses of NaP be taken 24 hours apart. Patients with renal failure, congestive heart failure and liver failure should avoid this preparation (Grade I A). PSMC is a hyperosmotic saline laxative which increases intraluminal volume resulting in increased intestinal motility. Magnesium, a constituent of PSMC, stimulates the release of cholecystokinin which also stimulates intestinal motility. Since magnesium is eliminated by the kidney, patients with renal insufficiency or failure should also avoid this preparation.

Many randomized controlled trials have compared the efficacy and tolerability of various bowel cleansing regimens. Studies comparing full-volume (4 liters) PEG with low-volume (2 liters) PEG combined with magnesium citrate or bisacodyl have demonstrated equal efficacy of colonic cleansing but with improved patient tolerance. However, there is little data on how low volume PEG compares with NaP. The only meta-analysis of twenty nine trials on optimal bowel preparation concluded that NaP was more effective in bowel cleansing than 4-liter PEG or PSMC. However, there were only three trials comparing NaP to PSMC that met inclusion and exclusion criteria in this meta-analysis and the results have been conflicting. Also there were only three trials comparing PEG to PSMC in this meta-analysis with inconclusive data. Moreover, the mean number of patients per trial was small at 223, with the highest number of patients in a trial at 500.

A consensus document prepared by three leading American gastrointestinal societies (American Society of Gastrointestinal Endoscopy, American Society of Colon and Rectal Surgeons and Society of American Gastrointestinal and Endoscopic Surgeons) as well as a position paper by the Canadian Association of Gastroenterology identified the lack of an ideal bowel preparation which meets all these criteria. Furthermore, the need for further studies was identified in the following areas:

  1. Two-liter PEG vs NaP
  2. PSMC vs NaP

Outpatients who need to undergo routine colonoscopy will be recruited. Each patient will be randomly assigned to one of the four bowel preparations after they have given consent to participate in the study:

  1. Group 1. 4L PEG.
  2. Group 2. 2L PEG plus 4 tablets of bisacodyl.
  3. Group 3. 90 cc NaP.
  4. Group 4. PSMC plus 1 bottle of Mg-citrate (300 cc).
Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary Purpose: Diagnostic
Condition  ICMJE Bowel Preparation
Intervention  ICMJE Procedure: colonoscopy bowel prep
PEG, bisacodyl, NaP, PSMC and Mg-citrate
Study Arms  ICMJE
  • Active Comparator: 1. 4L PEG only
    4L PEG PO
    Intervention: Procedure: colonoscopy bowel prep
  • Active Comparator: 2. 2L PEG plus bisacodyl
    2L PEG PO + 4 tablets bisacodyl PO
    Intervention: Procedure: colonoscopy bowel prep
  • Active Comparator: 3. NaP
    90 cc NaP PO
    Intervention: Procedure: colonoscopy bowel prep
  • Active Comparator: 4. PSMC plus Mg-citrate
    PSMC plus 300 cc Mg-citrate PO
    Intervention: Procedure: colonoscopy bowel prep
Publications *

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Completed
Actual Enrollment  ICMJE
 (submitted: June 9, 2016)
Original Estimated Enrollment  ICMJE
 (submitted: January 27, 2009)
Actual Study Completion Date  ICMJE July 2009
Actual Primary Completion Date July 2009   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Male or female between the ages of 18 and 75.
  • Planned elective outpatient colonoscopy.

Exclusion Criteria:

  • History of renal insufficiency or abnormal creatinine clearance with GFR <59.
  • History of congestive heart failure.
  • History of acute coronary syndrome or unstable angina.
  • History of liver cirrhosis or ascites.
  • Chronic lasix therapy.
  • History of colorectal resection.
  • Known or suspected bowel obstruction, megacolon or ileus
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years to 75 Years   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE Canada
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT00831064
Other Study ID Numbers  ICMJE 1-Kao
Has Data Monitoring Committee No
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Dina Kao, University of Alberta
Study Sponsor  ICMJE University of Alberta
Collaborators  ICMJE Not Provided
Investigators  ICMJE
Study Director: Sander van Zanten, MD University of Alberta
Principal Investigator: Din a Kao, MD University of Alberta
PRS Account University of Alberta
Verification Date June 2016

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP