Background: Use of antispasmodic medication prior to colonoscopy is controversial but may improve visualization of colonic mucosa and ease colonoscope insertion.
Method: The effects on the performance of colonoscopy by premedication with the antispasmodic hyoscine n-butyl bromide were studied in a prospective, double-blind, placebo-controlled trial. Fifty-six consecutive patients were randomly assigned to receive intravenous hyoscine 20 mg (n = 29) or placebo (n = 27) in conjunction with our standard initial medications (meperidine 0.7 mg/kg and midazolam 0.03 mg/kg). Insertion and withdrawal of the colonoscope were timed, and 100 mm visual analogue scales were used to assess procedure difficulty, colonic motility, and the degree of discomfort experienced by the patients.
Results: In those patients receiving hyoscine, intubation time was quicker (median hyoscine, 13 minutes; median placebo, 17.5 minutes, p = 0.045) and colonic spasm less (median hyoscine, 19 mm; median placebo, 53.5 mm, p = 0.01). The procedure was considered significantly less difficult in the hyoscine group (median, 23.5 mm) compared to the placebo group (median, 50), p <0.05. No significant differences in withdrawal time or patient pain scores were found.
Conclusions: Premedication with intravenous hyoscine n-butyl bromide reduces colonic spasm and in this study made colonoscope insertion significantly quicker and easier.