Pediatric abdominal pain is the most common clinical condition in pediatrics, and its etiology is diverse, among which mesenteric lymphadenitis is one of the common causes of pediatric abdominal pain, which has gradually increased in pediatric outpatient clinics in recent years. In the past, the main clinical considerations were biliary ascariasis or gastrointestinal spasm, but now, due to the widespread use of high-resolution ultrasound, pediatric mesenteric lymph nodes can be clearly displayed. At present, there are no uniform diagnostic criteria for pediatric mesenteric lymphadenitis at home and abroad, and there are few relevant reports. In this regard, the ultrasound images of mesenteric lymph nodes, treatment procedures and treatment results of 150 children with abdominal pain and a preliminary clinical diagnosis of mesenteric lymphadenitis in our hospital from June 2004 to October 2006 were statistically examined, with the aim of exploring the diagnostic criteria, differential diagnosis and treatment experience of pediatric mesenteric lymphadenitis. Clinical data This group of 150 outpatients with “abdominal pain” as the main complaint from June 2004 to October 2006, including 78 males and 72 females; the youngest was 3 years old, the oldest was 12 years old, and the average was 7 years old; the shortest duration was 1 week, and the longest was 3 years. The clinical manifestations were vague, dull or distending pain in the abdomen, mostly around the umbilicus, loss of appetite, nausea or abdominal distension, constipation, no fever or diarrhea. Physical examination: the face is less florid, the body is thin, and there is pressure pain around the umbilicus. Because of the underdeveloped abdominal muscles in children, abdominal muscle tension may not be obvious. About 72% of the children had a history of abdominal pain without other obvious positive signs. Routine blood tests in children with severe fever and abdominal pain showed elevated total leukocyte count in 13% of children and elevated neutrophils in 45%. Diagnostic method: Sequoia|512 color Doppler ultrasound diagnostic instrument with a frequency of 7.0 mhz was used, and the enlarged lymph nodes were clearly displayed in the supine position, in the order of right abdomen, periumbilical region and left abdomen. The location, size, echogenicity, morphology, and long/short axis ratio (l/s value) of the lymph nodes were observed and recorded, and confirmed by cdfi (color Doppler flow imaging). The results showed that all 150 children had multiple lymph node enlargement, and no single lymph node was seen. The maximum lymph node volume was about 24 mm × 9 mm × 9 mm and the minimum was about 7 mm × 5 mm × 5 mm. 26 cases (17%) had lymph nodes with a length of 5-10 mm, 118 cases (79%) had lymph nodes of 11-20 mm, and 6 cases (4%) had lymph nodes of >20 mm. Most of the lymph nodes were round or oval in shape, showing low-echo clusters with clear structure, and cdfi could clearly show blood perfusion in the lymph nodes. Treatment method The formula used to eliminate accumulation and relieve pain: mucuna pruriens 5 g, betel nut 10 g, Chen Pi 3 g, hedgehog shell 5 g, poria 10 g, atractylodes 5 g, dandelion 10 g, chicken naijin 5 g, white peony 10 g, licorice 3 g. Clinical evidence add and subtract: fever plus jinyinhua, forsythia pungent cooling and relieving symptoms; cough plus almond, zhebeimu to stop cough and resolve phlegm; constipation plus scape seeds, guajouren laxative; poor appetite plus malt, grain bud to eliminate food and strengthen stomach. The poor appetite adds wheat sprouts and grain sprouts to eliminate food and strengthen the stomach. The efficacy was counted after 15d. Treatment results Efficacy criteria (self-designed) Cured: clinical symptoms disappeared and no enlarged mesenteric lymph nodes were seen on ultrasound review. Effective: clinical symptoms basically disappeared, and the enlarged mesenteric lymph nodes were smaller than before treatment on ultrasound review. Ineffective: clinical symptoms and b-ultrasound review results did not improve after treatment. Among 150 cases, 113 cases were cured, 25 cases were effective and 12 cases were invalid, with a total efficiency of 92%. Pediatric mesenteric lymphadenitis is a non-specific inflammatory disease, the pathogenesis of which may be respiratory viral or bacterial infection causing mesenteric lymphadenitis in the mesenteric root, terminal ileocecal and ileocecal regions. The lymphatic system is an important defense device of the body. When an organ or part of the body is diseased, toxins, bacteria, etc. can reach the corresponding local lymph node via the lymphatic vessels. This local lymph node intercepts or removes these foreign substances and becomes a direct barrier to prevent the spread of the lesion, when the cells in the lymph node proliferate rapidly, function vigorously, and increase in size. However, the disease lacks typical clinical symptoms and specific tests, and often cannot be clearly diagnosed, and can only be treated symptomatically clinically, thus leading to recurrent episodes of the disease. According to clinical observation, the author experiences the following conditions should be considered as mesenteric lymphadenitis: upper respiratory tract infection or intestinal infection before the onset of the disease; clinical manifestations of fever, abdominal pain, vomiting and other symptoms; abdominal pain mostly located around the umbilicus, paroxysmal, spasmodic pain, less rebound pain and abdominal muscle tension; abdominal ultrasound suggests multiple mesenteric lymph nodes enlargement, and exclude other Common diseases causing abdominal pain.