The anatomical development of children varies by age and the pathology is naturally different. In newborns, the appendix is relatively short and thick and has a relatively large opening with a funnel-shaped root. The younger the age, the lower the incidence of pediatric appendicitis, which is clinically more common in school-aged children. The pathology of pediatric appendicitis is divided into the cicatricial, septic, gangrenous, and obstructive types. The khat type is only seen in the early stages of appendicitis in older children and may heal spontaneously in the late stages or turn into septic or gangrenous; the typical septic pathology is mostly seen in infants and young children, starting from the submucosa, with septic cell infiltration in all layers, swollen appendix, scarlet, with pus moss, clinically heavy abdominal pain and fever, obvious local pressure pain, and soon spread to peritonitis, especially in infants under 3 years old who have mostly become peritonitis at the time of consultation, due to fever, abdominal distension, The diagnosis is confirmed by fever, abdominal distension, hard abdomen, and pus through the abdomen; the gangrenous type is mostly seen in school-age children, with vascular embolism, rapid necrosis of the appendix, little peripheral exudation, but early fibrinopurulent adhesions, and easy formation of limited abscesses; the obstructive type is mostly seen in ascaris appendicitis and pinworm appendicitis, with no obvious changes in the appearance of the appendix, mostly in school-age children, with severe clinical abdominal pain and little pressure pain, generally no fever, and can occur without Secondary infection, the worm withdraws and heals, but the roundworm has burrowing, can press the tip of normal appendix perforation, multiple roundworms from this burrowing into the peritoneal cavity, forming roundworm peritonitis, the main pathology from mechanical stimulation, no purulent pathological reaction, clinical abdominal pain, pressure pain, fever are not serious, the disease develops slowly, there are chronic toxic symptoms, very similar to tuberculous peritonitis, but soon occur in the roundworm-centered multiple intra-abdominal The abscess is a severe toxic symptom, and the mortality rate of misdiagnosed late cases is very high. The pathology of pediatric acute appendicitis develops rapidly in He Xun, Department of Pediatric Surgery, Jiujiang Maternal and Child Health Hospital. The course of the disease in older children is generally within a week can also be divided into four stages: (1) simple appendicitis stage Various inflammatory changes are within the appendiceal organ. Peripheral exudation is low and the reaction is mild. The infection gradually spreads outward after about 12 to 24 hours of onset. (2) Period of infection spread Inflammation of the peritoneum around the appendix with pus, which gradually spreads to the whole abdominal cavity and becomes diffuse peritonitis. The younger the age, the faster it spreads, and after 48 hours, it is often the peritonitis phase. Clinically, there is fever, toxicity, abdominal distension, whole abdominal pressure and muscle tension. However, the right lower abdomen remains more pronounced. (3) Infection-limited stage Fibrin deposition in the exudate (pus moss), mutual adhesion of the appendix and surrounding organs to limit the spread of infection, peripheral exudate begins to be absorbed, and an infiltrative mass forms around the appendix, also known as the infiltrative stage. It is about the 3rd to 4th day after the onset of the disease and after 72 hours. The general condition of the child improves, with improvement in spirit and appetite compared to the previous day, but local pressure pain and muscle tension are prominent and limited. There is an infiltrative mass and pressure pain in the right lower abdomen on rectal palpation with double-combination of abdominal wall. (4) Appendiceal abscess stage The infection is limited and gradually absorbed and healed. However, if the appendix has become a necrotic foreign body or a fecal stone is trapped in the abdominal cavity, it becomes the core of the infection and forms an abscess, and the clinical fever remains but the abdominal pain gradually decreases. The pressure pain is still present and a spherical mass about 5-10 cm in diameter can be palpated (double coaptation). It forms in about 1 week and often takes several weeks to gradually resolve. The progression varies according to the type of pathology and age, with infants under 3 years of age rarely forming abscesses and developing peritonitis. In children under school age, the diffuse phase is not obvious and transitions directly to the limited phase. However, gangrenous forms are more common in school-aged children, while necrotic appendixes tend to form abscesses. In addition, post-onset medication has an impact. Large amounts of antibiotics may facilitate the transition to the limited stage or delay the spread, limit the spread, and alter the clinical course.