Pujahari 2010.

Methods	Randomised Controlled Trial
Participants	Patients with chronic anal fissure
Interventions	Unilateral internal sphincterotomy (110) versus Bilateral internal sphincterotomy (109)
Outcomes	Major and minor incontinence, fissure recurrence
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	sealed envelopes
Blinding of outcome assessment (detection bias) All outcomes	High risk	not stated
Drop‐outs All outcomes	Low risk	8/219 = 3.7%