The following situations can occur: 1. large intestinal lesions, such as diverticulitis, congenital megacolon, allergic colitis, may cause malfunction of the large intestine, spasm of the large intestine, resulting in feces can not move smoothly in the intestine, there will be the situation of wanting to defecate but can not be defecated. 2. defecation power is insufficient, defecation requires the anal sphincter muscle expansion, lifting the anal muscle to the upper and external pulling, and requires abdominal muscle contraction and diaphragm drop, and then force to expel the stool. 3. The company’s main business is to promote the development of the company’s products and services, Mental factors, long-term mental tension, anxiety and worry will also affect the gastrointestinal health, gastrointestinal peristalsis will slow down, a large amount of stool will accumulate in the intestines, the water in the stool gradually absorbed by the intestines become very dry, there will be want to defecate but can not be defecated.