Adults with enlarged abdominal lymph nodes may be commonly associated with lymphadenitis, malignant tumors, lymphatic tuberculosis and other diseases. 1. Lymphadenitis: mainly caused by abdominal infection, may be caused by bacterial or viral infection, such as enteritis, appendicitis, pancreatitis, etc., which will lead to inflammation of abdominal lymph nodes, and may appear enlarged phenomenon, you can take ampicillin, amoxicillin and other medicines under the guidance of the doctor for treatment. 2. Malignant tumor: Lymphoma is a malignant tumor originated from lymph nodes or other lymphatic tissues, which may appear symptoms such as swelling, distension and pain of lymph nodes, and can be treated by surgery or chemotherapy. And malignant tumors in abdomen, such as colon cancer, liver cancer, pancreatic cancer, bile duct cancer, stomach cancer, etc., may cause abdominal lymph node swelling through lymphatic metastasis. 3. Lymphatic tuberculosis: it means that tuberculosis bacilli multiply in the lymphatic system, thus forming lymphatic infection, which may lead to swollen abdominal lymph nodes, and can be treated by taking isoniazid, rifampicin, pyrazinamide, ethambutol and other medicines under the guidance of doctor. With abdominal lymph node enlargement, it may also be caused by other diseases. You should consult a doctor in time, complete the examination, clarify the cause and diagnosis, and standardize the treatment under the guidance of a professional doctor.