Mesalazine is commonly used in the treatment of Crohn’s disease and ulcerative colitis, which inhibits the synthesis of prostaglandins and leukotrienes, and also inhibits the release of prostaglandins, inhibits the migration and degranulation of neutrophils, inhibits platelet-activating factors, and thus inhibits the inflammatory response of the intestinal wall. The drug is usually administered one hour before meals, but the exact dosage of the drug should be decided by the doctor according to the disease, and the acute and maintenance phases, as well as the dosage of the drug for different diseases are different. The drug is relatively effective and has a relatively good safety profile. There is a possibility of mild stomach upset and head discomfort, such as nausea, headache, and dizziness, after using the drug. It cannot be used for patients with gastric and duodenal ulcers, and it is also contraindicated for patients who are allergic to its components.