The newborn’s stomach may be normal, such as after a full meal, crying, or may be abnormal (such as necrotizing small bowel colitis in newborns) can be seen abdominal distension. Newborns due to immature development of the digestive system, abdominal subcutaneous fat, weak muscle tissue and other factors, the abdomen is more prone to abdominal distension, that is, the “tummy bulging” phenomenon, but not all babies are abdominal distension. The age of the baby’s breathing for abdominal breathing, there can be a slightly inflated abdomen phenomenon, are normal physiological phenomena. When the newborn baby is not eating properly, the digestive tract can not tolerate, gastrointestinal dysfunction can be manifested in the above phenomenon, can be accompanied by spitting up more frequently than before, and even vomiting and other phenomena, or in neonatal necrotizing small bowel colitis disease, there can be obvious abdominal distension, can be accompanied by vomiting, bloody stools and other phenomena, belong to the pathology of the situation, and need to be actively consulted for intervention. Newborns with bulging tummies are advised to seek medical attention and be evaluated by a specialist for judgment.