Background: Chemical sphincterotomy with pharmacological agents is recommended as first line therapy for chronic anal fissures (CAF). Calcium channel blockers (CCB) are associated with similar efficacy but fewer side effects compared to nitrates. However, the optimal formulation (oral versus topical) is unknown. We aimed to perform a systematic review and meta-analysis to compare the effectiveness of oral and topical CCB in the treatment of CAF.Methods: PubMed and Embase online databases were searched for relevant articles. Two independent reviewers performed methodological assessment and data extraction. Random effects models were used to calculate pooled effect size estimates. A sensitivity analysis was also carried out.Results: Four randomized controlled trials describing 279 patients (138 in oral, 141 in topical group) were examined. There was significant heterogeneity among studies. On random effects analysis, topical CCB were associated with a significantly lower rate of unhealed fissure (21.3% vs. 38.4%; OR = 2.65, 95% CI = 1.50 to 4.69, p = 0.0008) when compared to oral therapy. However, there were no significant differences in fissure recurrence (5.4% vs. 5.5%; OR = 1.01, 95% CI = 0.31 to 3.33, p = 0.98) or side effects (15.6% vs. 39.1%; OR = 4.54, 95% CI = 0.46 to 44.3, p = 0.19) between topical and oral CCB. On sensitivity analysis, having excluded the most heavily biased trial, topical CCB were associated with significantly fewer side effects compared to oral therapy (4.3% vs. 38.0%; OR = 13.16, 95% CI = 5.05 to 34.3, p < 0.00001).Conclusions: Topical CCB are associated with better healing and fewer side effects when compared to oral therapy but there is no difference in recurrence rates. (C) 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.