Five-month-old baby three days without poop can be seen in physiological phenomena, functional constipation, etc., whether normal need to be based on the baby to judge, such as dry stools, defecation difficulties that the existence of constipation, it is not normal. 1. physiological phenomenon: for 5-month-old babies, especially formula milk-fed babies, there can be a relatively small number of bowel movements, such as intervals of 1 to 3 days to relieve a stool, but regular and smooth bowel movements, growth and development is normal, such as these babies appeared in the above phenomenon, is generally considered to be normal, but need to be observed dynamically. 2. Functional constipation: such as the above phenomenon and the baby’s previous bowel regularity compared to the interval significantly longer, part of the stool can be accompanied by dryness, defecation difficulties, the general view that the existence of functional constipation, that is not normal, the need to intervene when necessary. It is recommended that the five-month-old baby three days without poop timely consultation, by the specialist physician judgment after treatment. The above drugs should be used in accordance with medical advice.