Always have stool in the anus, need to consider the anal sphincter relaxation, anal fistula or internal hemorrhoids caused. The anal sphincter is located in the anal canal area of the muscle layer, divided into the internal sphincter and the external sphincter, the main role is to help control and discharge feces, such as sphincter relaxation, especially the long-term contraction to control the anal atresia of the internal sphincter relaxation, the anus may be unconscious relaxation of fecal exudate, resulting in long-term fecal matter residue in the anal opening. Anal fistula to typical anal fistula, for example, even if the anus is completely atresia, the feces in the rectal-anal tube will flow out of the anus through the internal and external orifices and fistulas directly outside the anus, and stay in the anal opening. Internal hemorrhoid development to stage IV, hemorrhoidal nuclei and enlargement will be prolapsed outside the anus embedded caused by anal atresia, feces and mucus will leak out of the body through the anal opening, will also cause feces in the anal opening for a long time, and most often accompanied by swelling, mild pain and other symptoms.