title: The effect on colon visualization during colonoscopy of the addition of simethicone to polyethylene glycol-electrolyte solution: a randomized single-blind study.
abstract: OBJECTIVE
  Colonic bubbles associated with polyethylene glycol-electrolyte solution (PEG-ELS) are common and obscure mucosal visualization. This study aimed to determine whether adding simethicone decreases the incidence of bubbles.
  
  
  METHODS
  Prospective, single-blind, randomized comparison of split dose PEG-ELS vs. PEG-ELS+simethicone (PEG-S) for outpatient colonoscopy. Bubble severity for colonic segments was assessed on withdrawal as A=no/minimal bubbles, B=moderate bubbles/interfere with detecting 5 mm polyp, C=severe bubbles/interfere with detecting 10 mm polyp. Primary end point was Grade B or C bubbles in any colon segment. Secondary end points were cleansing quality, incidence and severity of side effects, and polyp detection.
  
  
  RESULTS
  One hundred and thirty nine patients enrolled; 13 withdrew before colonoscopy. Of 123 patients evaluated, 62 took PEG-S and 61 PEG-ELS. The incidence of grade B or C bubbles was much lower with PEG-S compared with PEG-ELS (2% vs. 38%; P=0.001). Overall cleansing (excellent or good) quality was not significantly different for either the whole colon (89% PEG-ELS, 94% of PEG-S, P=0.529) or right colon (88% PEG-ELS, 94% PEG-S, P=0.365). More PEG-S patients had excellent rather than good preps (whole colon 53% vs. 28%, P=0.004; right colon 53% vs. 35%, P=0.044). Need for any flushing was less with PEG-S (38% vs. 70%, P=0.001). The groups were not significantly different with respect to total procedure and withdrawal times, incidence or severity of side effects, or number of polyps/patient or adenomas/patient.
  
  
  CONCLUSIONS
  Adding simethicone to PEG-ELS effectively eliminates bubbles, substantially reduces the need for flushing, and results in more excellent preparations.
authors.affiliation: Division of Gastroenterology and Hepatology, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Matro
authors.forename: Keegan
authors.initials: K
authors.lastname: Tupchong
authors.forename: Constantine
authors.initials: C
authors.lastname: Daskalakis
authors.forename: Victoria
authors.initials: V
authors.lastname: Gordon
authors.forename: Leo
authors.initials: L
authors.lastname: Katz
authors.forename: David
authors.initials: D
authors.lastname: Kastenberg