Eat into the stuff for several days to excrete, may be insufficient intake of dietary fiber, drinking less water and other physiological reasons, may also be intestinal obstruction and other pathological reasons. 1. Physiological reasons: usually too fine a diet, such as refined rice, cakes, desserts, etc., seldom eat spinach, celery and other coarse fiber foods, the gastrointestinal tract peristalsis is slow and little food residue, so less defecation, a few days once. Drinking too little water, the intestinal tract lack of water, stool dryness will also appear for several days to defecate once. With the aging of the elderly, gastrointestinal power is weakened, digestion and absorption of food is slow, may also occur once every few days, if the bowel movement is regular, there is no abdominal pain, abdominal distension and other uncomfortable symptoms, there is no need for treatment. 2. Pathological causes: intestinal obstruction leads to blockage of the intestinal tract and obstruction of stool discharge, which manifests itself as abdominal pain, abdominal distension and difficulty in defecation. Gastritis, gastric ulcer, duodenal ulcer and other diseases will lead to poor digestive function, reduced secretion of digestive juices, food is digested into the residue of the process of slowing down the gastrointestinal tract peristalsis slow, so it will be several days to defecate once. Normally, we should develop good dietary habits, regular meals, reasonable combination, chewing and swallowing when eating, avoid stimulating spicy food, drink more water. Appropriate sports exercise to promote gastrointestinal peristalsis. If the difficulty in defecation still does not improve, you should seek medical advice.