Background and study aims: Removal of colonic polyps prevents progression of colonic neoplasia. Miss rates of
polyps range from 5 % to 32 %. The effect of colonic contractility on polyp detection
has not been studied adequately. Hyoscine butylbromide results in colonic spasmolysis
and may improve polyp detection.
Patients and methods: Patients undergoing colonoscopy for standard indications were included and randomized
to receive either 20 mg hyoscine butylbromide or placebo at cecal intubation. Operators
were blind to the intervention. Data on indication, preparation, sedation, colonoscope
type, times of insertion/withdrawal, polyps, and failure were recorded. The primary
end point was the number of polyps detected per patient. Secondary endpoints were
adenoma detection rate and polyp detection rate.
Results: A total of 303 patients received hyoscine butylbromide and 298 received placebo.
More polyps per patient were identified in the hyoscine group than in the placebo
group (0.91 vs. 0.70; P = 0.044). Adenoma detection rate and polyp detection rate were higher in the hyoscine
arm but not significantly different (27.1 % vs. 21.8 % [P = 0.13] and 43.6 % vs. 36.6 % [P = 0.08], respectively). After adjusting for confounding variables, the odds of detecting
any polyp were 1.56 higher in the hyoscine than the placebo group (95 % confidence
interval [CI] 1.09 – 2.21, P = 0.014). The adjusted odds of detecting any adenoma were 1.62 higher in the hyoscine
group compared with the placebo group (95 %CI 1.09 – 2.42, P = 0.017). There were no differences in baseline characteristics between the groups.
No adverse colonoscopy-related events were recorded. One patient experienced transient
tachycardia without sequelae.
Conclusions: Hyoscine butylbromide administered at the cecum aids polyp detection. Further studies
are required to determine the contribution of colonic spasm to polyp miss rates.
