2 and a half year old baby three or four days stool once, if the stool is normal, not accompanied by stool pain, dryness and so on is normal, if accompanied by dryness, pain and so on is not normal. Two and a half year old baby three or four days stool once, if parents observe the normal nature of the stool, softer, defecation, the baby did not have pain, defecation difficulties, etc., is normal, may be a decrease in the amount of defecation, and the baby’s food intake, diet structure. If the baby dry stool, defecation difficulties, accompanied by defecation pain, crying is not a normal phenomenon, belong to constipation, need to investigate the existence of perianal disease, diet and other reasons, daily can give the baby more vegetables and fruits, these foods are rich in dietary fiber, can help intestinal peristalsis, more to take the baby to the outdoors, if accompanied by blood in the stool, abdominal pain and timely medical attention. Two and a half year old baby three or four days stool once, if there is no special discomfort can continue to observe, if constipation is recommended to appropriate abdominal massage, eat more vegetables and fruits, if necessary, under the guidance of a doctor to help relieve the use of drugs.