Causes of nausea, lack of appetite, and gastrointestinal dysfunction include functional gastropathy, gastritis, ulcer disease, and gastric cancer, and not all of them necessarily require a gastroscopy. Gastroscopy is not always necessary for gastrointestinal discomfort. If the gastrointestinal dysfunction is only caused by unclean diet and mental stress, and the symptoms are relatively mild, the patient can temporarily take medication to treat the symptoms, such as gastrointestinal tablets to promote digestion, omeprazole to inhibit acid and protect the stomach, domperidone to promote gastrointestinal dynamics, and so on, to observe the effectiveness of the treatment. If there is no significant relief of symptoms even after taking medication, or if there is a history of gastritis, gastric ulcer, or intestinal epithelial hyperplasia, gastroscopy should be performed to clarify the cause of the disease, and women should also pay attention to whether or not they are pregnant.