The most common cause of abdominal lymph node enlargement in children is mesenteric lymphadenitis, which is usually secondary to the onset of upper respiratory tract infection a week ago, with the main clinical manifestation being cough, accompanied by abdominal pain and discomfort, and easily misdiagnosed as acute appendicitis. In adults, once enlarged abdominal lymph nodes appear, they are usually secondary to malignant tumors of the gastrointestinal tract, commonly known as gastric or intestinal cancer, with metastasis of mesenteric lymph nodes. For adults with enlarged abdominal lymph nodes, the clinical manifestations are mainly vague abdominal pain and discomfort, which may or may not be accompanied by non-specific gastrointestinal symptoms such as nausea and vomiting. In case of intestinal tumor, complete or incomplete intestinal obstruction symptoms, that is, abdominal pain, abdominal distension, nausea, vomiting, may or may not be accompanied by complete cessation of bowel movement and exhaustion symptoms in the anus.