Vomiting in a 3-year-old child after eating a bad stomach may be caused by acute gastroenteritis, indigestion, etc. It is recommended to choose medication and general treatment to intervene under the guidance of a doctor. 1. Acute gastroenteritis: with acute gastroenteritis may appear vomiting symptoms, it is recommended to fasting, water, so as not to increase the burden on the stomach and intestines. For acute gastroenteritis caused by bacterial infection, antibiotic drugs and intestinal mucosal protectants can be chosen. Vomiting serious need to timely rehydration, so as not to cause electrolyte disorders. 2. Indigestion: Indigestion is caused by slow gastrointestinal peristalsis, which results in food staying in the stomach, and vomiting can also occur. It is recommended that the dietary structure be adjusted in a timely manner, with a light, easy-to-digest diet as the mainstay, and at the same time, the abdomen can be massaged appropriately to promote gastrointestinal peristalsis. At the same time can also be used under the guidance of a professional physician to help digestion of drugs, such as gastric digestion tablets, compound digestive enzymes and so on. Caused by 3-year-old children eat bad stomach vomiting causes more, it is recommended to go to the hospital in a timely manner, under the guidance of the doctor to clarify the specific causes of the disease, for the cause of the treatment.