title: 2-Litre polyethylene glycol-citrate-simethicone plus bisacodyl versus 4-litre polyethylene glycol as preparation for colonoscopy in chronic constipation.
abstract: BACKGROUND
  Chronic constipation is a risk factor of inadequate bowel preparation for colonoscopy; however, no large clinical trials have been performed in this subgroup of patients.
  
  
  OBJECTIVE
  To compare bowel cleansing efficacy, tolerability and acceptability of 2-L polyethylene-glycol-citrate-simethicone (PEG-CS) plus 2-day bisacodyl (reinforced regimen) vs. 4-L PEG in patients with chronic constipation undergoing colonoscopy.
  
  
  METHODS
  Randomized, observer-blind, parallel group study. Adult outpatients undergoing colonoscopy were randomly allocated to 2-L PEG-CS/bisacodyl or 4-L PEG, taken as split regimens before colonoscopy. Quality of bowel preparation was assessed by the Ottawa Bowel Cleansing Scale (OBCS). The amount of foam/bubble interfering with colonic visualization was also measured.
  
  
  RESULTS
  400 patients were enrolled. There was no significant difference in successful cleansing (OBCS score ≤6): 80.2% in the 2-L PEG-CS/bisacodyl vs. 81.4% in the 4-L PEG group. Significantly more patients taking 2L PEG-CS/bisacodyl showed no or minimal foam/bubbles in all colonic segments (80% vs. 63%; p<0.001). 2-L PEG-CS/bisacodyl was significantly more acceptable for ease of administration (p<0.001), willingness to repeat (p<0.001) and showed better compliance (p=0.002).
  
  
  CONCLUSIONS
  Split 2-L PEG-CS plus bisacodyl was not superior to split 4-L PEG for colonoscopy bowel cleansing in patients with chronic constipation; however, it performed better than the standard regimen in terms of colonic mucosa visualization, patient acceptance and compliance.
authors.affiliation: Gastroenterology Unit, A. Manzoni Hospital, Lecco, Italy. Electronic address: f.parente@ospedale.lecco.it.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Parente
authors.affiliation: Gastroenterology Unit, A. Manzoni Hospital, Lecco, Italy.
authors.forename: Cristian
authors.initials: C
authors.lastname: Vailati
authors.affiliation: Gastroenterology Unit, A. Manzoni Hospital, Lecco, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bargiggia
authors.affiliation: Gastroenterology Unit, L. Sacco University Hospital, Milan, Italy.
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Manes
authors.affiliation: Gastroenterology Unit, L. Sacco University Hospital, Milan, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Fontana
authors.affiliation: Gastroenterology Unit, S. Paolo University Hospital, Milan, Italy.
authors.forename: Enzo
authors.initials: E
authors.lastname: Masci
authors.affiliation: Gastroenterology Unit, S. Paolo University Hospital, Milan, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Arena
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Spinzi
authors.affiliation: Gastroenterology Unit, Valduce Hospital, Como, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Baccarin
authors.affiliation: Gastroenterology Unit, San Raffaele University Hospital, Milan, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Mazzoleni
authors.affiliation: Gastroenterology Unit, San Raffaele University Hospital, Milan, Italy.
authors.forename: Pier Alberto
authors.initials: PA
authors.lastname: Testoni
mesh_terms: D000368:Aged; D001726:Bisacodyl / Q000008:administration & dosage*; D002400:Cathartics / Q000008:administration & dosage* / Q000009:adverse effects; D002908:Chronic Disease; D019343:Citric Acid / Q000008:administration & dosage; D003106:Colon / Q000187:drug effects*; D003113:Colonoscopy / Q000592:standards*; D003248:Constipation / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011092:Polyethylene Glycols / Q000008:administration & dosage*; D012841:Simethicone / Q000008:administration & dosage
chemical_list: D002400:Cathartics; D001726:Bisacodyl; D019343:Citric Acid; D011092:Polyethylene Glycols; D012841:Simethicone
keywords: Bisacodyl; Bowel preparation for colonoscopy; Chronic constipation; Low volume bowel preparation; Ottawa Bowel Cleansing Scale; Polyethylene glycol; Simethicone; Split-dose