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

Aliment Pharmacol Ther. 2006 Sep 15;24(6):965-71. doi: 10.1111/j.1365-2036.2006.03080.x.


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% (< or = 5 mm), 5.9% (6-9 mm), 6.7% (10-19 mm), 2.1% (> or = 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 > or = 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / diagnosis
  • Clinical Competence
  • Cohort Studies
  • Colonic Neoplasms / diagnosis
  • Colonic Polyps / diagnosis*
  • Colonic Polyps / pathology
  • Colonoscopy / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Time Factors