Selection criteria All randomised controlled trials (RCTs) comparing any intervention for preventing postpartum constipation versus another intervention, placebo or no intervention. Interventions could include pharmacological (e.g. laxatives) and non-pharmacological interventions (e.g. acupuncture, educational and behavioural interventions). We included quasi-randomised trials. Cluster-RCTs were eligible for inclusion but none were identified. Studies using a cross-over design were not eligible for inclusion in this review. Data collection and analysis Two review authors independently screened the results of the search to select potentially relevant studies, extracted data and assessed risk of bias. Results were pooled in a meta-analysis only where there was no substantial statistical heterogeneity.