Patients with stomach pain and nausea may be suffering from acute gastroenteritis, peptic ulcer, pyloric obstruction or gastric cancer, as follows: 1. Acute gastroenteritis: Patients mostly suffer from improper diet, with gastrointestinal mucosa congestion, edema or with erosion, often with nausea, vomiting, bloating, diarrhea and abdominal pain. 2. Peptic ulcer: Patients will have chronic regular abdominal pain with nausea and bloating. 3. Pyloric obstruction: Peptic ulcer or polyps cause patients to have pyloric obstruction, they will have severe vomiting, abdominal pain with abdominal distension and other uncomfortable symptoms, and need immediate surgical treatment. 4.Gastric cancer: patients with gastric disease will have irregular stomach pain with nausea, weakness, abdominal distension, indigestion and other uncomfortable symptoms. Patients with stomach pain, nausea and other symptoms are recommended to visit gastroenterology department for systematic examination and give drug treatment. Usually, it is necessary to have a light and easy-to-digest diet, avoid cold, spicy, greasy and other stimulating foods, avoid strong tea, coffee, alcohol and other undesirable stimuli, and maintain regular rest and good mood to promote recovery.