6 months baby three days did not poop may be physiological causes, but also may be functional constipation, congenital megacolon and other diseases caused by different reasons for different ways of treatment, common treatments are general treatment, drug treatment, surgical treatment, etc.. 1. Physiological reasons: breastfeeding babies, due to breast milk nutrition is good, digested feces residue less, to stimulate the intestinal tract and promote intestinal peristalsis of the role of less, resulting in delayed defecation, can appear three days did not poop phenomenon. Need to pay attention to diet regulation, usually give the baby more warm water, give the baby’s abdominal massage, can relieve constipation. 2. Functional constipation: due to the weakening of gastrointestinal peristalsis and intestinal disharmony, caused by the baby three days did not poop phenomenon. Through the abdominal massage to improve, this method needs to adhere to, appropriate activities to do exercise, promote gastrointestinal peristalsis, can also follow the doctor’s instructions to the baby to take probiotics such as bifidobacteria to regulate intestinal flora, promote gastrointestinal peristalsis, can relieve constipation. 3. Congenital megacolon: the lack of ganglion cells in the colon leads to continuous spasm of the intestinal tract, and the feces stays in the proximal colon. Thickening and dilatation of the proximal colon is one of the common congenital intestinal disorders, which can occur when the baby does not poop for three days. In mild cases, corkscrew can be used to promote bowel movement. In severe cases, surgical treatment, such as colostomy, is needed. The baby did not poop for three days, exclude physiological reasons, it is recommended to consult a doctor in time to avoid delaying the condition. The above medications should be used in accordance with medical advice.