The Impact of Bowel Cleansing on Follow-up Recommendations in Average-Risk Patients With a Normal Colonoscopy

Stacy B Menees, MD, MS; Eric Elliott, MPH; Shail Govani, MD; Constantinos Anastassiades, MD; Stephanie Judd, MD; Annette Urganus, MPH; Suzanna Boyce, MPA; Philip Schoenfeld, MD, MSEd, MSc (Epi)


Am J Gastroenterol. 2014;109(2):148-154. 

In This Article


This is the first multicenter endoscopic database study to assess the impact of bowel preparation on endoscopists' recommendations to repeat colonoscopy in 10 years after a normal CRC screening colonoscopy. In our study, recommendations inconsistent with guidelines were provided in 23.9% of all cases, and fair bowel cleansing was strongly associated with inconsistent recommendations. These findings provide a starting point to establish an acceptable threshold for frequency of adherence to guideline recommendations as part of a quality improvement program and for development of national benchmarks by organizations such as CMS. These data also suggest that interventions that increase the frequency of excellent/good bowel preparation may minimize recommendations inconsistent with guidelines.

Our study methodology differs significantly from previous survey studies because it reflects actual practice, and is not influenced by response bias or the effect of a trial on endoscopists' behavior (i.e., Hawthorne effect).[16,24,25] Our study estimated that 75% of patients with a fair cleansing were instructed to have a repeat colonoscopy in <10 years compared with 15.3% with excellent/good preparations. This is consistent with our pilot study.[26] In multivariate analysis, fair bowel cleansing was associated with an 18-fold increase of receiving a recommendation inconsistent with guidelines compared with excellent/good bowel cleansing. Notably, 2012 multisociety CRC guidelines emphasize the importance of "adequate" preps that can identify polyps >5 mm vs. "inadequate." In the future, the addition of "adequate" or "inadequate" to bowel preparation classification will help determine if endoscopists provide recommendations consistent with guidelines.

Maximizing excellent/good preps may also maximize recommendations to repeat colonoscopy in 10 years after a normal screening colonoscopy. The PM/AM split-dosing of the bowel preparation increases the frequency of excellent/good bowel cleansing based upon current guidelines[2] and multiple randomized controlled trials.[27] Nevertheless, adoption of this standard has been gradual,[28] and many endoscopists continue to utilize PM-only bowel preparation protocols, possibly because of concerns that patients will be unwilling to rise early to complete the AM dosing of bowel preparation.[29] However, patients can be easily educated about split-dose bowel preparation.[2] Our data reflect outcomes with PM-only bowel preparation. If an endoscopist frequently reports fair bowel cleansing and frequently recommends repeat colonoscopy sooner than 10 years after a normal screening colonoscopy, then converting to PM/AM split-dosing may be the most appropriate quality improvement intervention.

Our study has several potential limitations. This is a retrospective study that reflects PM-only dosing of bowel preparation. There may also be variability among physician reporting of bowel preparation quality that is not captured. Although a validated scale to assess quality of bowel cleansing, such as the Boston Bowel Preparation Scale, was not used, the nonvalidated Aronchick scale is used widely,[18,30,31] and this may enhance the generalizability of our results.

In conclusion, our study demonstrates that endoscopists make recommendations inconsistent with guidelines frequently after a normal screening colonoscopy. Fair bowel cleansing is the factor most commonly associated with recommendations inconsistent with guidelines, and hence institution of protocols to improve bowel cleansing may be appropriate for suboptimal performers.