Anal fissures are not inside the anus, but occur outside the anus at the anal opening. Anal fissures are caused by poor dietary habits of the patient, which make the stool too dry and dehydrated. When the patient has a bowel movement, the skin around the anus tears due to the excessive pressure on the back wall of the anal canal, and the most common place for the fissure is right in the middle of the front and back part of the anus, which splits to form a small ulcer. It usually leads to a more intense pain around the anus and is accompanied by bleeding, which is brighter in color and does not bleed much, and requires local cleaning with potassium permanganate and then treatment with Ma Yinglong hemorrhoid cream, which can have the effect of removing decay and creating muscle. Therefore, anal fissures occur outside the anus, once they appear, it is best that you can go to the hospital for treatment in a timely manner.