Abstract
Background and study aims Female sex has been identified as a factor increasing patients’ pain during colonoscopy.
The aim of this randomized controlled study was to investigate the efficacy of a small-caliber
colonoscope, PCF-PQ260 L, for limiting pain in women during unsedated colonoscopy.
Patients and methods Women who underwent unsedated colonoscopy were randomly allocated to either the small-caliber
or standard colonoscope group. The primary outcome was overall pain and secondary
outcomes were maximum pain and procedural measures. In addition, the effects of colonoscope
type were analysed using analysis of covariance and logistic regression with adjustment
for stratification factors, age and prior abdomino-pelvic surgery.
Results A total of 220 women were randomly assigned to the small-caliber (n = 110) or standard
(n = 110) colonoscope groups. Overall and maximum pain scores were significantly lower
in the small-caliber colonoscope group than the standard colonoscope group (overall
pain, 20.0 vs. 32.4, P < 0.0001; maximum pain, 28.9 vs. 47.2, P < 0.0001). The small-caliber
colonoscope group achieved a superior cecal intubation rate (99 % vs. 93 %, P = 0.035).
The rate of patient acceptance of unsedated colonoscopy in the future was higher in
the small-caliber colonoscope group than in the standard colonoscope group (98 % vs.
87 %, P = 0.003). In addition, the small-caliber colonoscope was superior with respect
to reducing pain and improving the rate of patient acceptance of unsedated colonoscopy
with adjustment.
Conclusions This study demonstrates the efficacy of the small-caliber colonoscope for reducing
pain in women and improving their rate of acceptance of unsedated colonoscopy.
