IRCT2016110130623N1 IRCT 2017-09-13 Vice Chancellor for research of Kurdistan University of Medical Sciences Comparison of the three types of medical treatment; Topical application of Nitroglycerin plus Diltiazem Gel , Bethanechol Gel and Diltiazem Gel in healing chronic anal fissure Effect of topical application of Nitroglycerin plus Diltiazem compared with the two methods of topical use of Bethanechol and Diltiazem in the treatment of patients with chronic anal fissure 2016-10-21 anticipated 90 Complete https://irct.ir/trial/24269 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Other design features: A total of 90 patients were randomly divided into three groups of 30 subjects by blocking method. In order to blind the study, the drugs were given to patients by a nurse who was not sensitive to the results of the study. All of the patients' codes were kept by him until the data analysis phase, and the project executives were unaware of them until the end of the study Patients' visits were also carried out by a gastroenterologist who was not aware of the groups. N/A chronic anal fissure. Intervention 1: Interventional group 1: Combination therapy (1% Nitroglycerine ointment plus topical 5% Diltiazem gel as separate product), TDS for eight weeks. Intervention 2: Intervention group 2: bethanechol , 0.1% gel, topical, TDS for eight weeks. Intervention 3: Control group: diltiazem, 5% gel, topical, TDS for eight weeks.