title: Comparable Efficacy of a 1-L PEG and Ascorbic Acid Solution Administered with Bisacodyl versus a 2-L PEG and Ascorbic Acid Solution for Colonoscopy Preparation: A Prospective, Randomized and Investigator-Blinded Trial.
abstract: BACKGROUND
  Two liters of polyethylene glycol (PEG) solution administered with ascorbic acid (Asc) can provide efficacy similar to that of a 4-L PEG solution for colonoscopy preparation. In addition, oral bisacodyl (Bis) has been shown to reduce the volume of PEG needed for a bowel preparation with comparable efficacy. This study aimed to compare the efficacy, tolerability and safety of a 2-L PEG solution mixed with Asc versus the combination of Bis, Asc and a 1-L PEG solution.
  
  
  METHODS
  This was a prospective, randomized, multi-centre, single-blind, non-inferiority trial. Participants who were scheduled for colonoscopy were included and randomized to receive either 2-L PEG and Asc (2L PEG/Asc group) or 1-L PEG, Asc and 20 mg Bis (1L PEG/Asc + Bis group). The quality of bowel preparation was assessed using the Boston Bowel Preparation Scale. Data regarding tolerance, compliance and adverse events were also gathered.
  
  
  RESULTS
  A total of 187 participants were analyzed; 96 were allocated to the 2L PEG/Asc group and 91 to the 1L PEG/Asc + Bis group. Bowel preparation was adequate in 87.5% (84/96) of patients in the 2L PEG/Asc group and 94.5% of the 1L PEG/Asc + Bis group (86/91, p = 0.10). There was no significant difference between the two groups with respect to compliance, tolerability or safety. The patients allocated to the 1L PEG/Asc + Bis group expressed more willingness to repeat the procedure than patients in the 2L PEG/Asc group (p = 0.01).
  
  
  CONCLUSIONS
  Bowel preparation with Bis and a 1-L PEG/Asc solution is as effective, well-tolerated, and safe as a 2-L PEG/Asc solution.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT 01745835; Clinical Research Information Service (CRiS) KCT0000708.
authors: Department of Internal Medicine, The Armed Forces Capital Hospital, Bundang, Korea.
authors: Ji Eun
authors: JE
authors: Kwon
authors: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors: Jung Won
authors: JW
authors: Lee
authors: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors: Jong Pil
authors: JP
authors: Im
authors: Department of Internal Medicine, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors: Ji Won
authors: http://orcid.org/0000-0002-1214-5544
authors: JW
authors: Kim
authors: Department of Internal Medicine, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors: Su Hwan
authors: SH
authors: Kim
authors: Department of Internal Medicine, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors: Seong-Joon
authors: SJ
authors: Koh
authors: Department of Internal Medicine, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors: Byeong Gwan
authors: BG
authors: Kim
authors: Department of Internal Medicine, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors: Kook Lae
authors: KL
authors: Lee
authors: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors: Sang Gyun
authors: SG
authors: Kim
authors: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors: Joo Sung
authors: JS
authors: Kim
authors: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors: Hyun Chae
authors: HC
authors: Jung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001205:Ascorbic Acid / Q000008:administration & dosage*; D001726:Bisacodyl / Q000008:administration & dosage*; D002400:Cathartics / Q000008:administration & dosage*; D003113:Colonoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011092:Polyethylene Glycols / Q000008:administration & dosage*; D016037:Single-Blind Method; D055815:Young Adult
chemical_list: D002400:Cathartics; D001726:Bisacodyl; D011092:Polyethylene Glycols; D001205:Ascorbic Acid