OBJECTIVE There is wide variation in the use of antispasmodics to facilitate colonoscopy, both within and between countries, and its use before such procedures remains controversial. The aim of this study was to determine whether there was any objective benefit in using hyoscine as a premedication for colonoscopy in a district general hospital. METHODS Consecutive day-case patients undergoing colonoscopy were included in the study. They were prospectively randomly allocated to receive either intravenous hyoscine (n = 61) or intravenous placebo (n = 56) as part of their premedication. RESULTS Our analysis demonstrated no statistically significant difference between the two groups with respect to the median time from colonoscope insertion to caecal intubation (9.7 minutes in the hyoscine group vs. 8.3 minutes in the placebo group) or the median total procedure time (14.8 minutes in the hyoscine group vs. 13.8 minutes in the placebo group). There was also no statistically significant difference in success rates for caecal intubation between the two groups ( P < 0.06). However a type II error cannot be excluded because of the small sample size. CONCLUSIONS This study demonstrated no obvious benefit in the routine use of hyoscine as a premedication for colonoscopy in a district general hospital setting.