Impact of endoscopist withdrawal speed on polyp yield: Implications for optimal colonoscopy withdrawal time

D. T. Simmons, G. C. Harewood, T. H. Baron, B. T. Petersen, K. K. Wang, F. Boyd-Enders, B. J. Ott

Research output: Contribution to journalArticlepeer-review

189 Scopus citations


Background: In 2002, a U.S. Multi-Society Task Force on Colorectal Cancer recommended that the withdrawal phase for colonoscopy should average at least 6-10 min. This was based on 10 consecutive colonoscopies by two endoscopists with different adenoma miss rates. Aims: To characterize the relationship between endoscopist withdrawal time and polyp detection at colonoscopy, and to determine the withdrawal time that corresponds to the median polyp detection rate. Design: Procedural data from out-patient colonoscopies performed at the Mayo Clinic, Rochester during 2003 were reviewed. Endoscopists were characterized by their mean withdrawal time for a negative procedure and individual polyp detection rate. Results: A total of 10 955 colonoscopies performed by 43 endoscopists were analysed. Median withdrawal time was 6.3 min (range: 4.2-11.9); polyp detection rate was 44.0% (all polyps), 29.8% (≤5 mm), 5.9% (6-9 mm), 6.7% (10-19 mm), 2.1% (≥20 mm). Longer withdrawal time was associated with higher polyp detection rate (r = 0.76; P < 0.0001); this relationship weakened for larger polyps (r = 0.19 for polyps 6-9 mm, r = 0.28 for polyps 10-19 mm, r = 0.02 for polyps ≥20 mm). Overall median polyp detection rate corresponded to a withdrawal time of 6.7 min. Conclusion: Our findings support a colonoscopy withdrawal time of at least 7 min, which correlates with higher colon polyp detection rates.

Original languageEnglish (US)
Pages (from-to)965-971
Number of pages7
JournalAlimentary Pharmacology and Therapeutics
Issue number6
StatePublished - Sep 2006

ASJC Scopus subject areas

  • Hepatology
  • Gastroenterology
  • Pharmacology (medical)


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