Whether it is normal for a 3-month-old baby to have no poop for two days depends on the baby’s symptoms, and it is usually normal if the baby has no other discomforts. It is generally normal for a 3-month-old baby who has not pooped for two days but is in good spirits, eats a normal amount of milk, sleeps soundly, and does not have a hard stomach when touched. It may be related to the fact that the food residue produced after recent breastfeeding or formula feeding is relatively small and not enough to stimulate the rectum to produce a bowel movement response. If the baby has other discomforts, such as the baby loves to cry, the stomach is bulging and hard to touch, the amount of milk has decreased, sleep is not solid, easy to wake up, it is more abnormal phenomenon, it is recommended to consult a doctor to clarify the diagnosis. If your 3-month-old baby has not pooped for two days and is accompanied by other discomforts, it is recommended that you consult a doctor for a clear diagnosis so as not to miss the opportunity for treatment.