Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Symptom improvement
RCT 4-armed trial	160 people with chronic anal fissure	Mean time to complete pain relief 5.7 days (40 people) with open lateral internal sphincterotomy 15.7 days (40 people) with topical diltiazem	P <0.001	Effect size not calculated	open lateral internal sphincterotomy