Infants can drink milk when they reach one week of age. Before one week of age, infants’ spleen and stomach are weak in digestion and have poor resistance to milk proteins, so if they are given ordinary milk, they will develop milk protein allergies, causing vomiting, abdominal pain, diarrhea, and even blood in the stool, which can cause malnutrition in infants. It can also cause symptoms of indigestion in infants, such as bloating, thick and greasy tongue, and sour and smelly stools. When the infant reaches the age of one week, the spleen and stomach function is gradually perfected, and at this time the infant can gradually add milk from a small amount to a large amount, which most infants can slowly accept.