Failure of stool to reach the rectum may be caused by too little food, functional constipation, intestinal polyps and other reasons. 1. Eating too little: when patients eat too little for a long time, or the food they eat is mostly dilute fluid, there may be less digestive residue, and the stool cannot reach the rectum. 2. Functional constipation: Functional constipation refers to the constipation caused by the exclusion of organic lesions, mainly manifested as difficulty in defecation, hard stools or dry ball stools, reduced frequency of defecation, long time without bowel movement, etc. Functional constipation may also be caused by the failure of stool to reach the rectum. 3. Intestinal polyp: intestinal polyp is a kind of bulging lesion protruding from the surface of intestinal mucosa to the intestinal lumen, when the patient’s intestinal polyp may block the feces, residue to the rectal operation, so that there is a stool to the rectum can not be the case. When intestinal obstruction, after colostomy, etc., can also lead to the stool can not reach the rectum. Therefore, it is important to consult a doctor in time, complete the examination, make a clear diagnosis, and then follow the doctor’s instructions to treat accordingly.