Original article Clinical endoscopy| Volume 75, ISSUE 3, P537-544.e1, March 2012

Split-dose picosulfate, magnesium oxide, and citric acid solution markedly enhances colon cleansing before colonoscopy: a randomized, controlled trial

Published:December 23, 2011DOI:


      Picosulfate, magnesium oxide, and citric acid solution is a small-volume agent for colon cleansing before colonoscopy that is extremely well tolerated by patients, safe, and efficacious. Studies of other cleansing agents have suggested that split-dose regimens may further enhance efficacy.


      To examine whether split-dosing of picosulfate, magnesium oxide, and citric acid solution increases bowel cleansing efficacy while maintaining tolerability and safety.


      Prospective, randomized, single-blinded, controlled trial.


      Outpatient tertiary care center.


      A total of 236 patients underwent colonoscopy (mean age 56 years, 53.8% female).


      Patients in the traditional arm (n = 123) consumed 1 sachet of solution at 5:00 pm and 10:00 pm the night before the colonoscopy. Patients in the split-dose arm (n = 127) consumed 1 sachet at 7:00 pm the night before and another sachet 4 hours before their colonoscopy appointment.

      Main Outcome Measurements

      Ottawa Bowel Preparation Scale (OBPS) score, Aronchick score, safety, tolerability.


      The 113 and 109 patients in the split-dose and traditional arms, respectively, had OBPS scores for analysis. Overall, the OBPS scores in the split-dose group were significantly improved compared with the traditional dose group (4.05 vs 5.51, P < .001). This was mostly attributed to improvements in right-sided colon cleansing (1.22 in split-dose vs 2.14 in traditional arm, P < .001). Both regimens were well tolerated by patients, and no safety issues were identified.


      This was a single-center study. Disturbances in sleep related to the preparation were not assessed.


      The split-dose regimen of picosulfate, magnesium oxide, and citric acid solution is superior to the traditional dosing regimen for colon cleansing before colonoscopy. (Clinical trial registration number: NCT00885274.)


      OBPS (Ottawa Bowel Preparation Scale), PSLx (Pico-Salax)
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