0~3 months newborns do not defecate may be insufficient intake, functional constipation, organic constipation, etc., often need to take general treatment, medication, surgical treatment, etc.. 1. Insufficient intake: may be due to the amount of breast milk to the newborn or feeding the amount of milk powder is relatively small, not generate enough stool, which leads to not defecate, at this time must increase the amount of feeding, if the amount of breast milk is insufficient to add the appropriate amount of formula. 2. Functional constipation: Breastfeeding newborns are mostly overfeeding caused by the baby can be massaged abdomen, promote gastrointestinal motility, to help defecation; and formula feeding are mostly less water, can be appropriate to the newborns to feed the water, to help alleviate the symptoms. At the same time, oral probiotics such as bifidobacteria to regulate, and if necessary, can be used to help defecation. 3. Organic constipation: mostly caused by congenital intestinal malformations in newborns, such as congenital megacolon, which usually requires surgical treatment. 0~3 months newborns do not defecate should be timely consultation, identify the causes for targeted treatment. The above medications should be used in accordance with medical advice.