Stomach pain after eating is related to irregular diet, gastric ulcer, digestive tract tumor and other diseases. Pain in the stomach after eating is considered to be caused by bad eating habits. Eating a lot of stimulating food in a short period of time, smoking, drinking and overeating are more harmful to the stomach. Excessive food intake into the stomach causes the intestines and stomach to fail to peristaltic movement normally, which can cause pain in the stomach. Most patients with gastritis or gastric ulcer will have regular pain in the stomach after eating because the intake of more food causes dilation of the stomach, so the ulcer area will be painful. By taking oral acid-inhibiting drugs, such as omeprazole, the secretion of gastric acid is inhibited while the gastric mucosa is protected and the patient’s symptoms are alleviated. If after eating, the performance of stomach pain for a longer period of time, accompanied by black stool and obvious loss of body weight should be alarmed and considered to be caused by malignant tumor of digestive tract. As the tumor enlarges, it will stimulate the nerves in the stomach, which will also cause pain in the stomach.