There are many causes of nausea and stomach pain, and the common ones are acute gastroenteritis, acute cholecystitis, acute appendicitis and so on. 1. Acute gastroenteritis: it is an acute inflammation of the mucous membrane of the gastrointestinal tract, mostly caused by unclean diet or overeating. The main manifestations are nausea, vomiting, abdominal pain, bloating, diarrhea, fever and other symptoms. This causes nausea and stomach pain. 2. Acute cholecystitis: It is an inflammation of the gallbladder caused by obstruction of the gallbladder duct and other diseases or injuries. The main manifestation is sudden and persistent pain in the right upper abdomen after a full meal or eating greasy food, which may be accompanied by fever, nausea, vomiting, anorexia, loss of appetite and other symptoms. It can also cause nausea and stomach pain. 3. Acute appendicitis: inflammation of the appendix, a common surgical disease. Its typical symptom is metastatic right lower abdominal pain, which may be accompanied by decreased appetite, nausea, vomiting, fever, abdominal distension and other symptoms. It can also cause nausea stomach pain. There are many other causes of nausea and stomach pain, which should be taken seriously, and timely consultation should be made to identify the cause of the disease and follow the medical advice for further treatment or therapy.