Background: Acute fissure in ano, disease of young age is frequently associated with early hemorrhoids. The condition usually presents with severe pain, spasm and needs emergency Lateral internal sphincterotomy (LIS). Results of LIS are extremely rewarding. Additionally, effect of LIS on early hemorrhoids needs to be studied.Methods: Prospective observational study of 106 Patients of acute fissure in ano was conducted in Dr D.Y. Patil hospital and research center, Pune over 2 years. All the patients underwent emergency LIS and evaluated for symptomatic relief, complications and regression of the hemorrhoids diagnosed intraoperatively.Results: Acute fissure in ano is disease of young child bearing age group female (49%). Low fiber diet (75%) is associated with fissure. Lack of exercise and sedentary lifestyle are another factors. LIS is safe and effective tool to control pain and most of the other symptoms.86% patients get complete pain relief assessed by VAS score.98% patients are completely relieved after LIS. 95.2% patients got relief of anal spasm post-operatively.18% of the patients had early hemorrhoids and 70 to 80% of early hemorrhoids were completely reduced post LIS.Conclusions: Acute fissure in ano is the disease of young reproductive female with non-vegetarian diet, sedentary lifestyle, lack of exercise as risk factors. LIS is effective in reducing symptoms. VAS score is handy tool in assessing severity of pain and effectiveness of LIS. Complications with LIS are low making it safe procedure. Association of hemorrhoids with fissure appears insignificant. LIS appears to be effective in reducing the hemorrhoids with fissure.