Three months baby constipation can be seen in functional constipation, congenital megacolon and other conditions, there is no fast defecation method, need to give appropriate intervention according to the cause, such as functional constipation of the baby can be used to open the plug and microecological agents and other treatments. 1. Functional constipation: there is often a significant reduction in the number of bowel movements, or dry stools affect defecation and other symptoms. For 3-month-old babies can be used as appropriate to soften the stool, so that the stool is easy to discharge, need to pay attention to the use of the process of action gently, at the same time can be used as appropriate oral micro-ecological preparations (such as clostridium casei bacterial powder) to regulate the intestinal flora and other therapies. 2. Congenital megacolon: there can be delayed discharge of fetal stool, intractable constipation and other symptoms, children have different clinical manifestations due to different lengths of diseased intestinal tubes. For the treatment of this age group of babies can be used to expand the anus, corkscrew or laxatives to maintain daily defecation, so that its nutritional development to maintain at a normal level, assessed by specialists for elective surgical treatment, for the combination of infection or obstruction should be actively control the infection first, to relieve the obstruction and so on. All of the above medications should be used under the guidance of a doctor, avoiding self-medication, and it is recommended to go to the hospital in a timely manner, and be evaluated by a specialist to provide targeted treatment or therapy.