Generally, terminal ileitis is allowed to take mesalazine. Terminal ileitis is an inflammation of the end of the ileum, and patients with terminal ileitis may experience abdominal pain, diarrhea, abdominal mass, and fistula. Mesalazine is usually used to treat colitis, and this drug has a significant anti-inflammatory effect on the intestinal wall, so terminal ileitis can also take it. Some patients may experience adverse symptoms such as rash, drug fever, bronchospasm, chest pain, headache, dizziness, memory loss, diarrhea, nausea, vomiting, dry mouth, constipation, and arthritis after using Mesalazine. It should be noted that the use of this drug should be prohibited for those who are allergic to any of the components of mesalazine, those with severe renal failure, patients with bleeding, peptic ulcers, pyloric obstruction and so on. If the disease is diagnosed as terminal ileitis, it is recommended to carry out early standardized treatment in order to reduce the adverse effects of the disease. The drug needs to be used under the guidance of a doctor, and should not be used privately.