The poop of a 33-day-old baby just after breastfeeding may be a normal physiological phenomenon. If the stool is abnormal in character and color, it may be caused by pathological factors, such as lactose intolerance. 1. Physiological phenomenon: 33-day-old babies are not fully developed, and the anal sphincter is relatively weak, which can lead to uncontrolled bowel movements. In addition, 33-day-old babies will have gastro-colonic reaction after eating, that is, the peristalsis of the small intestine increases after the stomach is full, and at this time, if there is stool in the rectum, it will be discharged. This phenomenon will generally with the baby’s age, physical maturity and gradually alleviate, generally do not need special treatment. 2. Pathological factors: If the baby’s stool is abnormal in character and color, it may be due to lactose intolerance, indigestion and other reasons. If your 33-day-old baby has poop after breastfeeding, there may be other reasons, so we suggest that you go to the hospital in time, complete the examination to determine the cause of the disease, and then give targeted treatment under the guidance of the doctor.