Stomach pain and yellow water vomiting are associated with bile reflux gastritis, acute enteritis, and intestinal obstruction. When the pressure in the duodenum increases, the contents in the duodenum will reflux into the stomach and induce biliary reflux gastritis. Biliary reflux gastritis not only causes pain in the stomach, but also nausea and vomiting. Since the vomit will contain bile, the vomited material will appear yellowish in color. When acute enteritis is present, there is inflammation of the intestinal mucosa, which causes spasms and contractions of the intestine and even the discharge of intestinal fluid into the stomach, resulting in pain in the intestinal area and vomiting of yellow-colored intestinal fluid. Some people will have intestinal obstruction, and vomiting will occur because the contents above the obstruction cannot be removed, resulting in excessive dilatation of the intestinal wall and increased internal pressure. Some patients with intestinal obstruction also vomit out the digested food in the intestine when they vomit, so they may vomit yellow water, etc.