Terminal ileal lymphoid follicular hyperplasia is usually due to physiologic, inflammatory, or neoplastic causes. 1. Physiological causes. Mostly seen in children, usually found in abdominal ultrasound and other examinations, usually no obvious symptoms, without special treatment. 2. Inflammatory causes. Inflammatory causes generally include bacterial infection, viral infection or chronic intestinal inflammation. They are usually caused by chronic inflammatory diseases of the intestines such as chronic enteritis. In addition to the primary disease manifestations, abdominal pain, abdominal distension, nausea, vomiting and other discomforts may also occur. After the inflammation is controlled, lymphoid follicular hyperplasia will gradually disappear. 3. Tumor causes. Lymphatic metastasis of malignant tumor or lymphoma may cause lymphatic metastasis, resulting in lymphoid follicular hyperplasia at the end of ileum. In the early stage, patients may have no obvious discomfort, but as the lymphoid follicles gradually proliferate and enlarge, they may cause nausea, vomiting, abdominal distension and other discomforts due to compression of the ileum. If lymphoid follicular hyperplasia of the terminal ileum is found on examination, the cause of the disease should be identified and treated accordingly.