Right Or Left in COLonoscopy (ROLCOL)? A Randomized Controlled Trial of Right- versus Left-Sided Starting Position in Colonoscopy

Am J Gastroenterol. 2015 Nov;110(11):1576-81. doi: 10.1038/ajg.2015.298. Epub 2015 Sep 29.


Objectives: Colonoscopy is technically challenging and can cause discomfort for patients. We aimed to test whether right-sided starting position for colonoscopy would result in shorter procedure time and greater patient comfort when compared with conventional left-sided starting position.

Methods: We conducted a randomized controlled trial in which patients were randomized to begin in either the right- (RL) or conventional left-lateral (LL) position. One hundred and sixty-three adult patients undergoing scheduled colonoscopy were stratified by age, gender, body mass index, and experience of the endoscopist. Patients were then randomized 1:1 in permuted blocks. The primary outcome measure was time to cecal intubation and secondary outcome measures included patient comfort that was evaluated by visual analog comfort scale.

Results: Median time to reach the cecum was quicker when colonoscopy began with patients positioned RL rather than LL (P=0.0078). Moreover, patients found RL more comfortable than LL (P=0.02). Multiple linear regression confirmed starting position in colonoscopy as an independent determinant of time to reach the cecum (P=0.007). Women and those who had previously undergone abdominal surgery gained the greatest benefit from right-sided positioning (RL vs. LL: 498 vs. 824 s; P=0.03 and 498 vs. 797 s; P=0.006, respectively).

Conclusions: Our study reveals that right-sided positioning at the start of colonoscopy results in more comfortable and quicker procedures. Of the factors identified by multiple linear regression to independently have an impact on time to reach the cecum, only starting position is modifiable. Right-sided starting position may therefore be of benefit in colonoscopy, in particular for women and patients who have previously undergone abdominal surgery.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Cecum / pathology
  • Colonoscopy / adverse effects
  • Colonoscopy / methods*
  • Female
  • Humans
  • Intubation
  • Male
  • Middle Aged
  • Pain / etiology
  • Pain Measurement
  • Patient Positioning*
  • Patient Preference*
  • Sex Factors
  • Time Factors