Stomach pain and vomiting may be caused by bile reflux gastritis, peptic ulcer, gallstones and other factors, and need to consult a doctor in time for treatment. 1. Bile reflux gastritis: usually due to increased pressure in the intestines, the pyloric sphincter relaxation phenomenon, resulting in bile, pancreatic fluid and other contents into the stomach, when the inflammation stimulation, there will be abdominal pain and vomiting phenomenon, due to the presence of bile in the vomitus, so there will be a bitter feeling. 2. Peptic ulcer: usually due to the excessive secretion of gastric acid and pepsin, resulting in damage to the gastric mucosa, which leads to the phenomenon of stomach pain. When the emptying ability of the stomach is weakened, bile will not be able to enter the intestines quickly, thus bile will be retained in the stomach for a long time, which may cause the patient to vomit bitter water. 3. Gallstones: Because the stones are embedded in the gallbladder, they may affect the excretion of bile, thus causing stomach pain and bitter water. There may be other causes of stomach pain and bitter water, please consult a doctor for diagnosis in time, and usually eat a reasonable diet to protect the health of the gastrointestinal tract.