title: Colonoscopy using a small-caliber colonoscope with passive-bending after incomplete colonoscopy due to sharp angulation or pain.
abstract: BACKGROUND
  We evaluated the performance of a newly developed small-caliber (SC) colonoscope (PCF-PQ260L). This colonoscope (diameter 9.2 mm) is designed with passive-bending and high-force transmission. The SC colonoscope was used for rescue colonoscopy following incomplete colonoscopy with a standard (SD) colonoscope caused by sharp angulation, loop formation, or pain.
  
  
  METHODS
  Records of SC colonoscopy given to patients following an incomplete colonoscopy with the SD colonoscope and in the same session were analyzed. Cecal intubation rate, pain using a visual analog scale (0 = none, 100 = extremely painful) in the first and second colonoscopy, total time, new lesions detected with the SC colonoscopy, dosage of sedation used, and any complications were assessed. Examinations that could not be completed, because the colonoscope was not long enough to reach the cecum due to a redundant colon were excluded.
  
  
  RESULTS
  The records of 43 patients who were given SC colonoscopy following incomplete examinations using the SD colonoscope were reviewed. In 97.7 % of cases (42/43), cecal intubation was achieved with the SC colonoscope in the same session. The mean pain score during colonoscopy was significantly lower for the second SC colonoscopy than for the first SD colonoscopy (40.6 ± 14.1 vs. 74.5 ± 10.8, P < 0.001). Lesions were detected with the SC colonoscope in 41.8 % of cases (18/43).
  
  
  CONCLUSIONS
  When a colonoscopy with SD colonoscope failed due to sharp angulations, loop formation, or pain, subsequent colonoscopy with a SC colonoscope increased cecal intubation and lesion detection rates and decreased severity of reported pain.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Toho University Ohashi Medical Center, 2-17-6 Ohashi, Meguro-ku, Tokyo, 153-8515, Japan, koichiro.sato.0320@gmail.com.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Sato
authors.forename: Fumiko
authors.initials: F
authors.lastname: Shigiyama
authors.forename: Sayo
authors.initials: S
authors.lastname: Ito
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kitagawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Tominaga
authors.forename: Takeshi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Iruru
authors.initials: I
authors.lastname: Maetani
mesh_terms: D015746:Abdominal Pain / Q000209:etiology* / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002432:Cecum; D020685:Colonoscopes; D003113:Colonoscopy / Q000009:adverse effects* / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors