3 and a half year old baby drink water all vomit may be acute gastroenteritis, may also be the emergence of intestinal obstruction, gastrointestinal dysfunction and other problems. 1. Acute gastroenteritis, the baby appeared acute gastroenteritis due to bacterial viruses or other pathogens invade the baby’s intestinal tract, may lead to intestinal dysfunction, sensitivity increased, so there will be the symptom of drinking water all vomit. 2. Intestinal obstruction, the baby appeared after intestinal obstruction due to intestinal blockage may affect the normal digestion, so there will be 3 years old baby drink water all vomit symptoms. 3. gastrointestinal dysfunction, some babies have gastrointestinal dysfunction due to the intestinal tract is affected, may lead to such symptoms. 3 years old baby drink water are vomiting, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.