A newborn’s stomach is usually large and will bulge after feeding, just like a small drum. The baby’s abdominal wall muscles are not yet mature, but have to accommodate the same number of internal organs as adults. In the case of the abdominal muscles do not have enough strength to bear, the abdomen will therefore appear to be more protruding, such a situation is normal, but touch malice up if you feel very hard, there may be the following reasons: 1, indigestion, resulting in abdominal distension: newborns with hard tummies are more often seen in abdominal distension. Due to more gas in the digestive tract, generally newborns will have mild bloating after breastfeeding, but the doctor in touch with the abdomen is soft, without too much intervention. In general, you need to pay attention to the interval between each breastfeeding, the amount of breastfeeding and pay attention to the correct posture, do not let the baby cry for too long. 2, lactose intolerance and milk protein allergy: lactose intolerance and milk protein allergy can also cause bloating, you need to adjust the mother’s diet, plus lactase and other measures, and in severe cases, you need to change the lactose-free milk powder or even deeply hydrolyzed milk powder. 3, intestinal inflammation, or even intestinal obstruction or perforation of the digestive tract and other reasons can also cause abdominal distension, at this time the child will have restlessness, crying or reduced response and other manifestations, do not allow to touch the stomach, the need for special and timely treatment, 4, some children have congenital gastrointestinal developmental problems, such as intestinal stenosis, easy to cause obstruction, but also manifested as abdominal distension over the site of the obstruction. In short, newborn abdominal distension can be normal or problematic, if as hard as a small drum, it is still recommended to do a checkup.