Anal fissures are one of the common anorectal disorders. Based on reports, one in five people will develop anal fissures in their lifetime. An anal fissure is a superficial and longitudinal tear in the endoderm, distal to the dentate line, that continues down to the edge of the anus. Generally, there are two kinds of treatment for anal fissure: 1. Medical treatments and, 2. Surgical treatments. The goal of the current study is to find an effective medical treatment for this disorder. In line with this goal, effects of ANSIL gel (Silver nanoparticles with Tannic acid) on anal fissure patients were studied