Failure to poop can be caused by underfeeding, poor bowel habits, and intestinal obstruction. 1. Eating too little: If you eat too little, it may lead to a decrease in intestinal contents, and the amount of intestinal contents is not enough to cause a bowel reflex, and then the situation of not being able to poop. 2. Poor defecation habits: Whenever there is a desire to defecate, if you do not defecate in time, it may lead to dry stools, which may lead to the situation of not being able to poop. 3. Intestinal obstruction: When there is an obstruction in the intestines, the intestinal lumen may be narrowed or completely occluded, and the intestinal contents cannot pass through the obstructed area smoothly, resulting in the situation of not being able to poop. In addition to the above reasons, there are many other causes such as irritable bowel syndrome and digestive tract tumors. If the symptoms occur frequently or are accompanied by other digestive symptoms such as bloating, nausea and abdominal pain, it is recommended to consult a doctor in time and improve the colonoscopy, abdominal CT and other related examinations under the guidance of the doctor to clarify the cause and treat it actively so as to avoid delaying the condition.