The generic name for Classico is infliximab for injection. Ulcerative colitis is an immune disorder that requires lifelong treatment. If the patient responds well to infliximab treatment, the drug should be used for a long time. Ulcerative colitis is a chronic recurrent inflammatory disease that occurs in the colon and rectum and is a lifelong recurrent disease. The disease is most common in 20-40 years of age and is seen in both men and women. The lesions mostly involve the rectum and sigmoid colon, and the clinical manifestations mainly include abdominal pain, diarrhea, mucus, pus and blood stools, with remission alternating with episodes lasting for several years. The etiology of ulcerative colitis is still unclear, and is now mostly considered to be an autoimmune disease. Infliximab for injection is a biological agent mainly used in the treatment of rheumatoid arthritis, Crohn’s disease, ankylosing spondylitis, psoriasis, and has a certain therapeutic effect on prolonged ulcerative colitis. Since ulcerative colitis is a lifelong relapsing disease, if the patient responds well to treatment with infliximab for injection, long-term application is recommended with a view to achieving maintenance of remission. Unless there is a loss of response, blood levels and antibody testing are also required to determine the cause of failure and whether there is room for optimization. If there is no room for optimization, consider switching to another biologic. Patients with ulcerative colitis should follow medical advice and under the guidance of a doctor when using class K. Do not self-administer the drug, as it may cause adverse consequences.