Colonoscopy is considered the gold standard for detecting precancerous lesions in the bowel -
providing both diagnostic and therapeutic value. Colonoscopy is, ultimately, operator
dependent and relies on adequate visualization of these lesions. A multitude of studies have
been done to determine the best way to achieve luminal distention that provides the best
visualization to detect and remove adenomas. Recent literature has studied the effect of
position changes in colonoscopy. Position changes have been theorized to increase luminal
distention in the bowel - improving visualization and maneuverability through the colon. Both
air and water are used during colonoscopy, with air rising in a dependent fashion in the
colon to the highest point. The standard position to perform colonoscopy is left lateral
decubitus. In this position, parts of the bowel collapse as air rises into other parts of the
bowel. This includes the sigmoid colon and the cecum, both of which are not fixed and can
therefore collapse becoming technically challenging to maneuver around. In the right lateral
decubitus position, the air rises into these unfixed areas of bowel and are easier to
maneuver. A trial by Vergis et al found that right lateral decubitus resulted in quicker
examination times and more comfort in their cohort of patients as opposed to the left lateral
decubitus position. The investigators note, however, that the population in which this study
took place are not comparable to the patients in Newfoundland and in Canada. The
investigators also note a study by Ou et al that found position changes had no effect in
adenoma detection. Furthermore, a study by Ball et al found conflicting results with position
change increased adenoma detection in the right but not the left side of the colon.
Conflicting results between all these trials and the populations used have lead to us
question if position changes, a cost free and technically easy intervention, can increase
visualization in colonoscopy. The investigators propose a randomized controlled trial that
compares positioning patients in the right lateral decubitus or left lateral decubitus to aid
in luminal distention and visualization, decreasing cecal intubation time and ultimately
increasing adenoma detection rate in colonoscopy.
In this trial, participation in the study will be offered when patients present for their
scheduled colonoscopy. The patients will be consented at this time for both the colonoscopy
procedure and participation in the trial. Patients who consent to take part will then be
randomly assigned to either the right or left lateral decubitus starting position. The
colonoscopy will then be done in the usual manner with appropriate sedation. Timing
throughout the colonoscopy, the number of polyps found and quality of the visualization will
then be recorded during the procedure. Patients will then be debriefed regarding their
colonoscopy following the procedure in recovery.