The most common clinical cause of pain on the left lower border of the rib cage after eating is digestive system diseases, such as chronic gastritis, gastric ulcer or gastric bleeding. After eating, the peristalsis of the gastrointestinal tract increases, and the local inflammatory response becomes more obvious, and pain can occur. It is mainly manifested as soreness, stabbing pain or colic, and local pain can be induced when pressed by hand, and sometimes rebound pain may occur. For this condition, the main treatment is medication to protect the stomach and inhibit gastric acid secretion, such as omeprazole enteric tablets, famotidine, and magnesium aluminum carbonate. If the medication is not effective, or if the symptoms gradually worsen, gastroscopy is recommended to further clarify the diagnosis and then take corresponding treatment plans. The second cause is relatively rare and may be inflammation of the costal cartilage or intercostal neuralgia, which is not related to eating, with localized pressure pain and a more severe pain level.