Primary outcomes
The primary outcome was defined as the level of abdominal pain felt with change of position (according to the VAS scale) at 8 hours after surgery. Based on previous studies 3,17, it was estimated that each intervention (administration of SC and/or IP analgesia) would result in a 20% reduction in the primary outcome, as compared to non-intervention (administration of SC or IP placebo). In order to attain a power of 80% and a significance level of 0.05, the total sample size required was calculated to be 25 patients for each group. We included 30 patients in each group, in order to make up for any potential loss of follow up.