It is normal for a month old baby to not have a bowel movement for a day. Since the gastrointestinal function of the baby is not yet well developed, it is easy to have indigestion, so not having a bowel movement for a day is usually not a big problem and there is no need to worry too much. In addition, the number of bowel movements of infants is related to the feeding method, breast-fed babies have more bowel movements, perhaps 5-6 times a day. Babies who are artificially mixed-fed have fewer bowel movements because the palm oil in the formula tends to dry out the stool, resulting in less easy or fewer bowel movements. If the baby does not have a bowel movement for a day, parents should observe whether the baby has any abnormal manifestations or symptoms, such as bloating, crying, vomiting, etc. They should also pay attention to the presence of anal venting. If the infant’s anal discharge is normal and there are no abnormal signs and symptoms, and if the infant eats milk normally, no special treatment is needed. However, if the infant does not have bowel movements for more than five days, the anal canal can be lubricated with a corked solution to assist in bowel movements. Probiotics, such as Bacillus subtilis dibacterium and Bifidobacterium bifidum, can also be taken for regulation. If there are other abnormal symptoms or if the infant does not have a bowel movement after using the above methods, the infant should be taken to the hospital promptly to find out the cause and exclude any other organic pathology.