The reasons for not being able to pass stool are mainly due to: 1, dietary factors, mainly eating some indigestible food, mainly food containing less dietary fiber, such as fine grains, greasy food, high protein food, etc., because these foods contain less dietary fiber, can not promote intestinal peristalsis; contains less water, can not soften the stool; food containing less slag, produce less stool, will lead to dry stool, produce 2, intestinal factors, mainly the intestinal function is weakened, mainly in the elderly and children, due to the weakening of intestinal peristaltic function, after eating the gastrointestinal food through the decomposition of gastric acid, bile and pancreatic juice into the intestinal absorption, the resulting feces can not be discharged through the peristaltic movement of the intestine, and the inability to defecate. 3, intestinal obstruction, mainly the intestinal peristaltic movement and excretion of the body. The main cause of intestinal obstruction is infection, intestinal stenosis or obstruction caused by adhesions after intestinal surgery, and the stool does not go down smoothly, resulting in failure to pass stool.