A 4-month-old baby without stool for a week may be a normal physiological phenomenon, or it may be caused by pathological phenomena such as constipation, intestinal obstruction and other reasons. 1. Normal physiological phenomenon: commonly found in 4 months exclusively breastfed babies, a week without stool, this is because the baby’s ability to digest and absorb more and more, resulting in a decrease in the number of feces, unable to promote intestinal discharge of feces. 2. Constipation: 4-month-old exclusively breastfed babies have no stool for a week. If the breast milk is insufficient and the baby is bedridden for a long period of time, the intestinal peristalsis is slow, and the water in the feces is absorbed again and again, and the feces is dry and constipated. 3. Intestinal obstruction: intestinal obstruction will appear to stop gas defecation, etc., resulting in 4 months exclusively breastfed baby 1 week no stool, often crying, vomiting, poor mental state and other manifestations. If the symptoms of a 4-month-old baby without stool for 1 week appear, it is recommended to go to the hospital in time for early and regular treatment.