Terminal ileitis is not necessarily Crohn’s disease, but may also be caused by other reasons, such as malignant tumors of the digestive tract, such as lymphoma, intestinal infections, such as EBV, cytomegalovirus, and so on. 1. Crohn’s disease: most common in the end of the ileum, can also involve the small intestine and colon, the lesions are mostly segmental distribution, can also be limited to a place, can be seen fissure-like deep ulcers, the surface of the cobblestone-like changes, intestinal wall thickening, granuloma formation, can lead to intestinal lumen narrowing. 2. Malignant tumors of digestive tract such as lymphoma: cecum and colon are the most common sites. Primary gastrointestinal lymphoma is often asymptomatic at the initial stage, with the development of the disease, some non-specific gastrointestinal symptoms and signs gradually appear, and the more common clinical manifestations include abdominal pain, abdominal mass, malnutrition, bleeding, perforation, incomplete obstruction and so on. 3. Intestinal infections such as EB virus and cytomegalovirus: enterovirus infections are infectious diseases caused by enterovirus, the clinical manifestations of which are only malaise and low-grade fever in the mild cases, but in the severe cases, they can be systemic infections, with damages to the brain, heart, liver and other vital organs, which have poor prognosis, and may leave sequelae or cause death. The finding of inflammation at the end of the ileum is not necessarily Crohn’s disease, and needs to be combined with clinical manifestations, endoscopy, pathohistology, imaging and clinical biochemical examination to make a comprehensive judgment.