The possible causes of enlarged mesenteric lymph nodes 2.1×0.8 cm include: mesenteric lymphadenitis, inflammatory bowel disease, intestinal malignant tumors, and so on. 1. Mesenteric lymphadenitis: mesenteric lymphadenitis is mostly seen in infants and children, mainly manifested as non-specific fever, abdominal pain, nausea, vomiting, diarrhea, etc., especially abdominal pain is more obvious, and the location is not fixed, it can be located in the umbilicus or right lower abdomen. Abdominal ultrasound can find mesenteric lymph node enlargement. 2. Inflammatory bowel disease: ulcerative colitis, Crohn’s disease and other inflammatory bowel disease can also cause mesenteric lymph node enlargement, mostly in young people, patients often have a long history of disease, recurrent, prolonged. 3 Malignant tumor lymph node metastasis: colorectal cancer is prone to lymphatic metastasis, which causes enlargement of adjacent lymph nodes, and mesenteric lymph node metastasis suggests that the condition is in progress. Mesenteric lymph node enlargement is also seen in other reasons, so it is suggested that patients should go to hospital as early as possible for consultation, so as to clarify its nature in time and give appropriate treatment to avoid delaying the condition.