The mesenteric lymph nodes are the lymph nodes inside the mesentery of the small intestine or the mesentery of the colon in the abdominal cavity, and they belong to the second station of the lymph nodes. The lymph nodes are usually enlarged when there is inflammation in the abdominal cavity or when there is a tumor in the colon. When inflammation causes lymph node enlargement, it is manifested in pain and hidden pain around the navel. The incidence is relatively high among adolescents, which is caused by bacterial infection, generally oral antibiotics or intravenous antibiotic treatment can be. If the lymph node enlargement is caused by a tumor, there is usually a primary lesion, usually in the small intestine or above the colon or rectum, and lymph node enlargement may occur along the mesentery. Surgery usually requires complete removal of the tumor and clearance of the lymph nodes within the mesentery.