Background: The treatment of chronic anal fissure, in recent years, has seen inclusion of various non surgical modalities to the gold standard i.e. lateral sphincterotomy. It was the attempt of this research to objectively ascertain the roles of various modes of therapy in treatment of chronic anal fissure and alsoto find correlation between decrease in sphincter pressures and decrease in pain with treatment, if any. Methods: A total of 102 patients were included in the study and randomized to receive medical or surgical treatment. 52 patients were managed with Glyceryl trinitrate ointment (0.2%) while 50 patients underwent lateral internal sphincterotomy. Objective assessment of the pain was recorded as per the Visual Analog Score before and after treatment. Mean basal anal sphincter pressures were recorded before and after treatment. All patients were assessed for fissure healing at 4 and 6 weeks after completion of treatmen . Results: The reduction in pain score was significantly higher in the patients treated surgically  (p =0.037). The reduction in sphincter pressure was also significantly higher in the surgical group at 25.10, while in the medical group it was 6.56 (p < 0.001).Fissure healing rates were significantly higher in surgical treatment group at 92 per cent versus 55.76 per cent. The correlation between reduction in pain in anal canal and reduction in the MASP was found to be significant (p=0.00; r=0.488). Conclusion: This is the largest study in Indian patients comparing chemical with surgical phincterotomy using reduction in anal pressures and pain along with fissure healing as outcomes. It showed that the reduction in pain and anal sphincter pressure as well as fissure healing is significantly better in patients undergoing surgery.

Keywords: Anal fissure; Anal sphincter pressure; Sphincterotomy.