Five months baby two days without stool, common causes include physiological causes and functional constipation, can be used to open oral medication, general measures to improve. 1. physiological reasons: five months baby for pure breastfeeding, breast milk food residue, with the baby digestion and absorption ability to improve, it takes a few days to form a stool, there may be 7-10 days a stool, the baby’s spirit, the amount of milk, sleep is good, abdominal soft, the stool is yellow soft stool, is a normal phenomenon, no need for special intervention. 2. Functional constipation: five-month-old babies if formula-fed, formula milk food residue, generally have regular bowel movements, if the baby longer than ordinary regular bowel movements, accompanied by defecation difficulties, dry stools, etc., may be functional constipation, parents can clockwise massage the abdomen, but also allow the baby to appropriate activities, to promote intestinal peristalsis. If necessary, use corkscrew to stimulate defecation. If the five-month-old baby two days without stool, and accompanied by other discomforts, it is recommended to consult a doctor in a timely manner, active treatment. The above drugs need to be used in accordance with medical advice.