Scope of treatment: Hemorrhoids: including internal, external and mixed hemorrhoids. Anal fistula: including high anal fistula, low anal fistula, complex anal fistula, recurrent anal fistula, etc. Anal fissure: including acute anal fissure and chronic anal fissure or with anal stenosis. Rectal perianal abscess. Rectal prolapse. Chronic outlet obstruction type constipation, etc. Benign diseases in and around the rectum and anus such as rectoanal injury and foreign body.