title: Efficacy of morning-only compared with split-dose polyethylene glycol electrolyte solution for afternoon colonoscopy: a randomized controlled single-blind study.
abstract: OBJECTIVE
  Administering a purgative close to the time of colonoscopy is optimal for cleansing. The aim of this study was to compare the efficacy and tolerability of morning-only (AM-only) polyethylene glycol electrolyte solution (PEG-ELS) to split-dose (PM/AM) PEG-ELS for afternoon colonoscopy.
  
  
  METHODS
  This was a single-center, prospective, randomized, investigator-blinded, non-inferiority study comparing AM-only to PM/AM PEG-ELS for afternoon outpatient colonoscopy. The primary end point was whole colon prep adequacy. Tolerance and polyp detection were secondary outcomes.
  
  
  RESULTS
  Overall, 125 patients were randomized and 9 withdrew without taking any prep. Of 116 analyzed, 62 received AM-only prep and 54 received PM/AM prep. The whole colon prep was adequate in 92% in the AM-only group vs. 94% in the PM/AM group (95% lower confidence limit, LCL, for the difference=-11.3%, non-inferiority P=0.013), whereas the right colon prep was adequate in 93 and 92%, respectively (95% LCL=-7.8%, non-inferiority P=0.003). Polyp detection was greater, and not inferior, in the AM-only group (mean=1.57 vs. 0.94 polyps/patient, non-inferiority P=0.007). The overall incidence of adverse events was not significantly different between the two groups (P=0.273), but the AM-only group had lower incidence of abdominal pain (P=0.024). The AM-only group also had better sleep quality (P=0.007) and less interference with the previous workday (P=0.019).
  
  
  CONCLUSIONS
  AM-only and PM/AM PEG-ELS are clinically equivalent with respect to cleansing efficacy and polyp detection. AM-only prep was associated with a lower incidence of abdominal pain, superior sleep quality, and less interference with workday before colonoscopy.
authors.affiliation: Department of Internal Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Matro
authors.forename: Anastasia
authors.initials: A
authors.lastname: Shnitser
authors.forename: Maya
authors.initials: M
authors.lastname: Spodik
authors.forename: Constantine
authors.initials: C
authors.lastname: Daskalakis
authors.forename: Leo
authors.initials: L
authors.lastname: Katz
authors.forename: Alexandra
authors.initials: A
authors.lastname: Murtha
authors.forename: David
authors.initials: D
authors.lastname: Kastenberg
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D002400:Cathartics / Q000008:administration & dosage / Q000627:therapeutic use; D003113:Colonoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011092:Polyethylene Glycols / Q000008:administration & dosage* / Q000627:therapeutic use; D011446:Prospective Studies; D016037:Single-Blind Method; D016896:Treatment Outcome
chemical_list: D002400:Cathartics; D011092:Polyethylene Glycols