There are the following weight possibilities for 3-year-old babies with tummy pain: the first one, due to poor digestion or gastrointestinal dysfunction. Babies often show paroxysmal pain in the abdomen, sometimes accompanied by nausea, vomiting and other symptoms. Serious symptoms of diarrhea may occur. Second, it may also be due to mesenteric lymph node inflammation, which is the main cause of abdominal pain in babies in the clinic, due to the stimulation of inflammation leads to abdominal lymph node swelling and pain. Third, may also be due to surgical diseases, such as clinical formation of intestinal hernia, as well as intussusception, intestinal malformation may appear abdominal pain symptoms. Therefore, for the 3-year-old baby abdominal pain, must go to the regular hospital for a detailed examination, to find the exact cause of the disease.