The main reasons why three-month-old babies drink milk and do not absorb it are improper feeding, functional indigestion and intestinal flora dysbiosis. 1. improper feeding: if the three months baby feeding too often, so that the amount of milk feeding beyond the digestive capacity of the baby’s digestive tract, will lead to the baby to drink some of the milk can not be digested in a timely manner, absorption. 2. Functional dyspepsia: If a three-month-old baby has a high sensitivity of internal organs, triggering functional dyspepsia, it will lead to the drink of milk not absorbed. 3. Intestinal dysbiosis: Due to the low immunity of three-month-old babies, the intestinal tract may be infected by pathogenic bacteria such as Enterobacteriaceae and Enterococcus, while the number of Bifidobacteria decreases, thus causing intestinal dysbiosis. Because the intestinal microecological imbalance can lead to diarrhea, bloating, indigestion and other symptoms, so the baby drink milk is not absorbed. Three-month-old babies drink milk is not absorbed, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.