IRCT2013042812294N3 IRCT 2013-10-21 Vice chancellor for research, Tehran University of Medical Sciences Partial Lateral Internal Sphincterotomy Versus Combined Botulinum Toxin A Injection and Topical Application of Diltiazem in Treatment of Chronic Anal Fissure Partial Lateral Internal Sphincterotomy Versus Combined Botulinum Toxin A Injection and Topical Application of Diltiazem in treatment of chronic anal fissure 2010-03-21 anticipated 99 Complete https://irct.ir/trial/12381 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. 2-3 Chronic Anal Fissure. Intervention 1: Intervention group: Under local anesthesia (with lidocaine 5% gel) on left sided or knee elbow position. BTA is injected into the internal anal sphincter on the both sides of anterior midline in equal doses. These patients will be advised to receive 2% DTZ ointment three times daily for six weeks which applied to the perianal region and anus. Intervention 2: Control group: under spinal anesthesia in the lithotomy position; internal sphincter muscle fibers were partially cut at 3 o’clock position under direct visualization with a transverse incision up to the height of the fissure apex using a cautery. In this study, skin tags and hypertrophied anal papillae were also removed.