A one-week-old child who vomits when he eats is mainly considered to be caused by the following reasons: firstly, gastrointestinal dysfunction, if the gastrointestinal dysfunction, the child will vomit when he eats, and often accompanied by abdominal pain, abdominal distension, and undigested food or milk petals in stools, and so on. In this case, you can give your child probiotics, such as Pepcid, Mommy Love, etc. for treatment. Because probiotics have the role of regulating intestinal flora disorders, gastrointestinal dysfunction has obvious improvement effect. The second consideration is caused by acute gastroenteritis, this kind of children often have eat too much food or eat unclean food diet history, often also have abdominal pain, fever and other discomforts, often diarrhea. This situation should be timely to the child for anti-infection treatment, can choose cephalosporin III drugs for treatment.