There are many causes of gastrointestinal discomfort, and the more common causes are as follows: 1. Caused by diet, for example, many people experience gastrointestinal discomfort, such as abdominal distension, abdominal pain, and even nausea and vomiting, after eating cold, greasy, and spicy foods. 2. Functional gastrointestinal disease, mainly gastroscopy does not see any abnormalities, while there are symptoms of indigestion and gastrointestinal discomfort. 3. Benign lesions, such as Gastritis, gastric ulcer, gastric erosion, gastric polyp, intestinal polyp, enteritis and other diseases. In addition, malignant lesions of the stomach and intestines may also show symptoms of gastrointestinal discomfort, such as stomach cancer, intestinal cancer, lymphoma, etc.