The constant stomach pain indicates the presence of inflammation, gastric ulcer, gastric cancer and intestinal cancer in the stomach. When inflammation occurs on the gastric mucosa, the gastric mucosa will be accompanied by congestion and edema, and these people will feel pain in the stomach after eating food because of the irritation caused by excessive secretion of gastric acid to the mucosa. The pain symptoms caused by gastritis are relatively mild but last for a long time. In some people, there are ulcers on the mucous membrane of the stomach, and in these people, food rubs against the ulcer surface when ingesting food, thus causing pain. Also, when stomach acid comes in contact with the ulcer surface, it can cause spasms in the stomach, and spasmodic pain can occur in the stomach. The degree of pain caused by gastric ulcer is more severe and has a certain pattern. Stomach cancer is a malignant tumor that causes damage to local tissues when the disease enters an advanced stage, and patients will suffer from long-lasting stomach pain. When the stomach pain is located in the lower abdomen, it should be alerted to bowel cancer, which will not only cause stomach pain but also accompany with diarrhea and bloating.