Abstract
Background Water filling during colonoscopy improves several colonoscopy outcomes. We evaluated
an anecdotal observation that room temperature water filling during colonoscope insertion
results in mucus production in the left colon, which may impair mucosal visualization
during withdrawal.
Methods We performed 55 colonoscopies with either water or saline filling during insertion,
and video recorded the examinations. Three blinded observers scored the amount of
mucus visible on the video recordings.
Results 29 patients had water filling and 26 patients had saline filling during insertion.
Demographic features, procedure indications, volume of infused fluid, and insertion
time to the cecum were similar in the two groups. All three blinded observers rated
the mucus as greater after water filling than after saline (median 3 out of 5 vs.
1 out of 5; P < 0.001), with a kappa value for interobserver agreement of 0.364 (P < 0.001).
Conclusion Room temperature water filling is associated with mucus production by the rectosigmoid
colon, requiring additional cleansing during withdrawal.
