Enlarged mesenteric lymph nodes may be caused by different factors such as simple inflammation or tumor invasion. 1. Simple inflammation. Mesenteric lymphadenitis caused by simple inflammation is most common in the terminal ileum. It is often manifested as fever, abdominal pain and other symptoms in clinic. Anti-inflammatory drugs such as cephalosporin can be chosen for conservative treatment, and it is recommended to take appropriate drugs under doctor’s treatment. 2. Tumor invasion. When the tumor invades into the small intestine and large intestine, it forms cancer foci, which will affect the lymph nodes around the cancer foci and make them enlarge gradually. Clinical symptoms may include abdominal pain, obvious decrease in appetite, obvious weight loss, anemia, blood in stool or change of bowel habit. It is suggested that patients should go to the hospital as soon as possible for systematic examination by doctors and actively cooperate with the treatment after diagnosis. The medication should be prescribed by the doctor.