Gupta 2008.
| Methods | Randomised Controlled Trial | |
| Participants | Patients with chronic anal fissure | |
| Interventions | Closed sphincterotomy (43) versus Sphincterolysis (42) | |
| Outcomes | Incontinence, fissure healing | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement | 
| Random sequence generation (selection bias) | Low risk | adequate | 
| Blinding of outcome assessment (detection bias) All outcomes | High risk | inadequate | 
| Drop‐outs All outcomes | Low risk | 4/85 = 4.7% |