The criteria for determining anal canal stenosis after hemorrhoid surgery mainly depends on whether there is difficulty in defecation, change in bowel habits, defecation accompanied by pain or bleeding, anal incontinence, and difficulty in inserting the finger of anal finger-diagnosis. 1. Difficulty in defecation: If the anal canal is narrowed after hemorrhoid surgery, the anus loses its elasticity, which leads to the phenomenon that feces is not easy to pass when defecating. 2. Changes in bowel habits: If the anal canal is narrowed after hemorrhoid surgery, there will always be a feeling of incomplete evacuation when having a bowel movement, resulting in prolonged bowel movement or an increase in the number of bowel movements. 3. Pain or bleeding during defecation: due to the difficulty of defecation, friction of feces and other effects, the anal area is often accompanied by pain or bleeding and other symptoms. 4. Anal incontinence: due to the narrowing of the anal canal after hemorrhoid surgery, the anus loses its elasticity, and the contraction function deteriorates accordingly, incontinence may occur, such as unconscious fecal discharge. 5. Difficulty in inserting the index finger in anal diagnosis: If the anal canal is narrowed after hemorrhoid surgery, the index finger can not be inserted into the anus smoothly when the professional doctor does anal diagnosis, or the index finger barely passes through the anus, but the anus is too tight, and through the touch of the finger, it will be felt that the anus is hard around the anus. Therefore, anal canal stenosis after hemorrhoid surgery can be identified by the several criteria mentioned above. Once the suspected manifestation of anal canal stenosis occurs, it is recommended to go to the regular hospital for consultation and examination as soon as possible, and the professional doctor will make professional judgment based on clinical manifestations and anal diagnosis and so on.