3 year old baby fever stomach pain, mainly consider the infection caused by gastrointestinal dysfunction, acute gastroenteritis and acute abdomen and other factors. 1. Gastrointestinal dysfunction: most of the baby fever is caused by bacterial and other pathogenic infections, at this time, the body inflammatory response. Inflammatory response can involve the digestive tract, causing gastrointestinal dysfunction, resulting in loss of appetite, diarrhea, abdominal pain and other symptoms. 2. Acute gastroenteritis: acute gastroenteritis occurs when the digestive tract is infected with pathogens, causing gastrointestinal dysfunction and symptoms of fever and abdominal pain. 3. Acute abdomen: such as pediatric intussusception, due to intestinal blood flow obstruction or intestinal necrosis, abdominal pain can occur, accompanied by fever at the same time. 3-year-old baby fever stomach pain, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.