Children with stomach pain and swollen lymph nodes may be associated with upper respiratory infections, intra-abdominal organ infections and lymphatic system disorders. 1. Upper respiratory tract infections: children with viral or bacterial upper respiratory tract infections may develop stomach pain and swollen lymph nodes as a complication. 2. Infection of abdominal organs: Infection of abdominal organs may cause inflammation of mesenteric lymph nodes in the abdominal cavity, resulting in reactive enlargement of mesenteric lymph nodes, which may cause gastrointestinal symptoms such as abdominal pain, nausea and vomiting. 3. Lymphatic system diseases: if the child’s stomach pain is accompanied by generalized lymph node enlargement, then consider whether there is a lymphatic system disease, such as lymphoma, etc., and must immediately take the child to the hospital for diagnosis and treatment. There are other reasons for children’s stomach pain and enlarged lymph nodes, parents are advised to take their children to the hospital for regular examination and treatment.