title: Randomized trial of 2-L polyethylene glycol + ascorbic acid versus 4-L polyethylene glycol as bowel cleansing for colonoscopy in an optimal setting.
abstract: OBJECTIVE
  Prior studies have reported 2-L polyethylene glycol (PEG) plus ascorbic acid (PEG + Asc) is an effective alternative to standard 4-L PEG for bowel preparation before colonoscopy, but they are limited because of some confounders. Therefore, we compared the efficacy, patient compliance, satisfaction, and safety of 2-L PEG + Asc versus 4-L PEG for bowel cleansing in optimal preparation strategies.
  
  
  METHODS
  In this prospective, randomized, single-blind trial, consenting outpatients were randomly assigned to one of two arms. All colonoscopies were scheduled in the morning and cleansing solutions were administered as a split-dose regimen. Bowel-cleansing efficacy in three different segments was measured on a five-point scale with four-point overall grading. Patients' opinions of the preparation regimens were obtained by questionnaire.
  
  
  RESULTS
  There was no significant difference between the 2-L PEG + Asc (159/163; 97.5%) and 4-L PEG (162/164; 98.8%) with respect to the overall success of bowel cleansing (mean difference = -1.3 [-4.1-∞]). Patient compliance, acceptability, and satisfaction were better in the 2-L PEG + Asc arm than the 4-L PEG arm (P < 0.05). Additionally, the incidence of side effects was lower in the 2-L PEG + Asc than the 4-L PEG (overall, 57.7% vs 73.2%, P < 0.05). However, no significant difference was seen in patients' rating of taste.
  
  
  CONCLUSIONS
  In an optimal preparation setting, 2-L PEG + Asc has equal efficacy as a bowel cleanser prior to colonoscopy as 4-L PEG, with the advantages of better patient compliance, satisfaction, and safety.
authors: Chang Mo
authors: CM
authors: Moon
authors: Dong Il
authors: DI
authors: Park
authors: Young Ghil
authors: YG
authors: Choe
authors: Dong-Hoon
authors: DH
authors: Yang
authors: Yeon Hwa
authors: YH
authors: Yu
authors: Chang Soo
authors: CS
authors: Eun
authors: Dong Soo
authors: DS
authors: Han
mesh_terms: D000368:Aged; D001205:Ascorbic Acid / Q000008:administration & dosage*; D002400:Cathartics / Q000008:administration & dosage*; D003113:Colonoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D011092:Polyethylene Glycols / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D016037:Single-Blind Method; D012996:Solutions; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D002400:Cathartics; D012996:Solutions; D011092:Polyethylene Glycols; D001205:Ascorbic Acid