A four and a half month old baby who has not pooped for 6 days may be caused by indigestion, intestinal obstruction, constipation and other reasons. 1. Indigestion: If the baby’s recent breastfeeding is relatively large, or the gastrointestinal function is weak, indigestion may occur, resulting in 6 days without poop. Parents can massage the baby’s abdomen clockwise to promote defecation. 2. Intestinal obstruction: Intestinal obstruction is due to various reasons leading to obstacles in the passage of intestinal contents, which may also lead to the baby not having bowel movements for 6 days. Parents can observe whether the baby has any abnormal situation, such as whether there is abnormal crying phenomenon, the baby if abnormal crying may be due to abdominal pain caused by intestinal obstruction. 3. Constipation: If the baby has constipation, the baby will not poop for a long time. If the baby is seriously constipated, it is recommended to seek timely medical attention. There are many reasons why a four-and-a-half-month-old baby doesn’t poop for six days, so it is recommended that you take your baby to the hospital to find out the cause and then treat the symptoms.