Abstract : The surgical intervention on chronic anal fissure is still the first line of treatment for this disease. The importance of this research lies in finding a new treatment for one of the most common anal lesions, and to choose a safe and effective method in the treatment of chronic anal fissure, avoiding the risks of anesthesia and surgery. To compare the surgical treatment (Lateral Internal Sphincterotomy) and topical treatment (Diltiazem Gel 2%), in terms of the ability to heal, studying the degree of symptoms regression after the treatment (bleeding/pain), and studying the incidence of gas / fecal incontinence. A prospective pilot study, which included 60 patients divided into two groups equally, Group A (30 patients who underwent surgical treatment), Group B (30 patients who underwent topical drug treatment with Diltiazem 2% gel), and the study was conducted at Tishreen University Hospital in Latakia – Syria, in the period between 2019-2020. In group A, complete recovery occurred in 29 patients (96.6%), anal bleeding decreased in all patients (100%), pain feeling decreased in all patients (100%), and gas incontinence occurred only in 4 patients (13.3%). Fecal incontinence didn't occur. In group B, complete recovery occurred in 17 patients (56.6%), anal bleeding decreased in 17 patients (68%), pain feeling decreased in 17 patients (65.3%), and gas / fecal incontinence didn't occur at all. Lateral internal Sphincterotomy is still the first line of treatment in patients with a chronic anal fissure, but drug therapy with (Diltiazem 2% gel) can be applied to patients who refuse surgical treatment, or for those who have contraindications for surgical intervention