There is stool can not pull always in the anal opening blocked, may be constipation, congenital anal deformity, rectal occupation and other reasons. 1. Constipation: due to low activity, slow peristalsis can lead to stool in the colon to stay too long to lose water, there can be dry stool, defecation difficult phenomenon. 2. Congenital anal deformity: it can cause narrowing of the anal area, and the phenomenon of not being able to pull out the stool, which is always blocked in the anal opening. 3. Rectal occupation: such as anal tumor, rectal cancer or polyps, internal hemorrhoids and other reasons can lead to narrowing of the anal area, preventing the discharge of stool. It is recommended that people who can’t pass stools are always blocked in the anus, go to the hospital in time, clarify the cause, and carry out standardized treatment under the guidance of professional doctors, and follow the doctor’s instructions.