There are several conditions: 1, intestinal tract problems, such as foreign bodies in the intestines, which will lead to stool can not be smoothly discharged from the body, so there will be no stool situation. In addition, there are stool color change, frequent stomach pain symptoms. 2, constipation, now many people’s diet structure is not very reasonable, the amount of daily exercise and very little, long-term so the peristaltic capacity of the gastrointestinal tract will become weak, the intestinal tract of the stool peristalsis to the anal area will take a long time, so there will be the situation of stool effort, and has not been the will to defecate. 3, eat too little food, eat too little, the The food residue in the intestine is particularly small, although it will produce stool, but the amount of stool is particularly small, it takes several days to defecate once, so it will temporarily appear the situation of straining to defecate. 4, eat too much too fine food, such as rice, steamed buns, etc., and the intake of coarse fiber food is particularly small, such as fresh fruits and vegetables, so the food residue in the intestine is also relatively small, so there will also be no stool The situation.