title: Water immersion colonoscopy facilitates straight passage of the colonoscope through the sigmoid colon without loop formation: randomized controlled trial.
abstract: OBJECTIVE
  One of the major causes of pain during colonoscopy is looping of the instrument during insertion through the sigmoid colon, which causes discomfort by stretching the mesentery. There are many studies in colonoscope techniques, but they have not been assessed objectively with respect to colonoscope passage through the sigmoid colon without loop formation. The aim of the present study was to determine whether cap-fitted colonoscopy and water immersion increase the success rate of insertion through the sigmoid without loop formation.
  
  
  METHODS
  A total of 1005 patients were randomized to standard colonoscopy, cap-fitted colonoscopy or water immersion technique. All examinations were carried out under a magnetic endoscope imaging device. Main outcome was the success rate of insertion without loop formation.
  
  
  RESULTS
  Success rate of insertion without loop formation was 37.5%, 40.0%, and 53.8% in the standard, cap, and water groups, respectively (standard vs water P = 0.00014, cap vs water P = 0.00186). There were no significant differences among the groups regarding cecal intubation rate, cecal intubation time and number of polyps ≥5 mm per patient.
  
  
  CONCLUSIONS
  Water immersion increases the success rate of insertion through the sigmoid colon without loop formation. This practical technique, requiring only preparation of a cap and water, is useful without compromising cecal intubation rate, cecal intubation time, or polyp detection rate.
authors.affiliation: Department of Gastroenterology, Tane General Hospital, Osaka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Asai
authors.forename: Naoki
authors.initials: N
authors.lastname: Fujimoto
authors.forename: Koujirou
authors.initials: K
authors.lastname: Tanoue
authors.forename: Eisuke
authors.initials: E
authors.lastname: Akamine
authors.forename: Eisuke
authors.initials: E
authors.lastname: Nakao
authors.forename: Kirie
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Takumi
authors.initials: T
authors.lastname: Ichinona
authors.forename: Mikio
authors.initials: M
authors.lastname: Nambara
authors.forename: Seitarou
authors.initials: S
authors.lastname: Sassa
authors.forename: Hideo
authors.initials: H
authors.lastname: Yanagi
authors.forename: Norifumi
authors.initials: N
authors.lastname: Hirooka
authors.forename: Takuji
authors.initials: T
authors.lastname: Mori
authors.forename: Minoru
authors.initials: M
authors.lastname: Ogawa
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Ogawa
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D012809:Colon, Sigmoid; D003111:Colonic Polyps / Q000175:diagnosis*; D020685:Colonoscopes; D003113:Colonoscopy / Q000379:methods*; D016292:Procedural Sedation / Q000379:methods; D005260:Female; D006769:Hospitals, General; D006801:Humans; D007101:Immersion; D008297:Male; D008874:Midazolam / Q000008:administration & dosage; D008875:Middle Aged; D015999:Multivariate Analysis; D010147:Pain Measurement; D056888:Patient Positioning; D018570:Risk Assessment; D014867:Water
chemical_list: D014867:Water; D008874:Midazolam
keywords: cap-fitted colonoscopy; colonoscopy; water exchange; water immersion; water navigation