title: Suboptimal Bowel Preparation Significantly Impairs Colonoscopic Detection of Non-polypoid Colorectal Neoplasms.
abstract: BACKGROUND
  It is unclear whether the quality of bowel preparation affects colonoscopic detection of non-polypoid colorectal neoplasms (NP-CRNs).
  
  
  OBJECTIVE
  To evaluate the impact of bowel-cleansing quality on detection of NP-CRNs.
  
  
  METHODS
  We performed a retrospective analysis of asymptomatic screening colonoscopy cases after standardized bowel preparation at an academic teaching hospital between June 2011 and May 2013. Primary outcome was a comparison of the adenoma detection rate (ADR) of non-polypoid morphology according to quality of bowel preparation. Secondary outcomes included detection prevalence of non-polypoid adenomas.
  
  
  RESULTS
  Of the enrolled 6097 screening examinations, the preparation quality was rated as adequate (excellent or good) in 5224 (85.7 %), fair in 615 (10.1 %), and poor in 258 (4.2 %) patients. The prevalence of NP-CRNs was 40.5 % (1962/4847) of all CRNs. The overall ADR of non-polypoid morphology was 12.3 % (747/6097) of all colonoscopies, but it significantly differed among participating endoscopists (all P < 0.05). The ADR of non-polypoid morphology was significantly lower with fair- or poor-quality preparation, versus adequate-quality preparation (adjusted odds ratio [aOR] 0.55, 95 % confidence interval [CI] 0.41-0.75; aOR 0.49, 95 % CI 0.30-0.79, respectively). Poor-quality preparation was also associated with impaired detection of polypoid, proximal colon, and sub-centimeter adenomas (all P < 0.05).
  
  
  CONCLUSIONS
  Suboptimal (fair or poor) bowel preparation significantly impairs colonoscopic detection of NP-CRNs. Given that the prevalence of NP-CRNs is substantial in our average-risk screening cohort, ongoing efforts to improve the preparation quality are practically valuable in increasing the detection of NP-CRNs, thereby improving the efficacy of screening colonoscopies.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kyung Hee University School of Medicine, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 130-701, Korea, harrison@daum.net.
authors.forename: Chi Hyuk
authors.initials: CH
authors.lastname: Oh
authors.forename: Chang Kyun
authors.initials: CK
authors.lastname: Lee
authors.forename: Jung-Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Jae-Jun
authors.initials: JJ
authors.lastname: Shim
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Jang
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D058070:Asymptomatic Diseases; D002400:Cathartics / Q000627:therapeutic use*; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003113:Colonoscopy; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000175:diagnosis*
chemical_list: D002400:Cathartics