Girls with pain in the lower stomach may have mesenteric lymphadenitis or acute appendicitis. General mesenteric lymphadenitis pain nature to be on the lighter side, the main location in the navel around and below the navel, usually one week or two weeks before the onset of the disease, there is a history of upper respiratory tract infection. Bacterial infection leads to enlargement of the mesenteric lymph nodes in the abdominal cavity, and abdominal ultrasound reveals enlarged lymph nodes in the mesentery, while the appendix is normal in morphology. Treatment is mainly oral antibiotics, such as cefixime. If appendicitis is present, it usually manifests as pain in the lower right side of the abdomen, but in the early stages of appendicitis, pain may also be present in the upper abdomen or around the navel. Appendiceal ultrasound can be performed to further clarify, if the ultrasound found that the appendix is swollen, there is oozing around the appendix, it can be diagnosed as appendicitis, after the diagnosis is clear, it is recommended that laparoscopic appendectomy be performed.