Vomiting in one and a half year old babies may be caused by improper diet, or it may be caused by other diseases such as acute gastroenteritis, and acute abdomen. 1. Improper diet:The symptoms of vomiting in a one-and-a-half-year-old child may be due to the child eating too much, or overeating easily increases the burden on the gastrointestinal tract, which may lead to the phenomenon of vomiting. 2. Acute gastroenteritis: Acute gastroenteritis is caused by bacterial, viral and other pathogenic infections, the child will appear diarrhea, abdominal pain, nausea, vomiting and other symptoms. As a result, one and a half year old babies appear to vomit. 3.Other:Acute abdomen, intestinal obstruction, meningitis and other diseases can also lead to one and a half year old baby vomiting phenomenon. One and a half year old baby vomiting may also have other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.