Acute appendicitis is an acute inflammation of the appendix, which is both the most common disease occurring in the appendix and the most common reason for abdominal surgery due to severe acute abdominal pain. Therefore, about 15% of patients who undergo surgery for acute appendicitis have abdominal pain caused by other reasons. Therefore, it is important to pay attention to the presence of abdominal pain in children and to seek timely medical attention. Signs and symptoms The typical signs and symptoms of acute appendicitis are: metastatic right lower abdominal pain, i.e., sudden onset of pain in the upper abdomen or around the umbilicus, followed by transient nausea and vomiting; after a few hours, the pain shifts to the right lower abdomen. The typical site of pressure pain in the right lower abdomen is located at McBurney’s point (the outer and middle third of the line between the anterior superior iliac spine and the umbilicus) and is characterized by fixed pressure pain in the right lower abdomen. There may be limited pain on coughing. It is often accompanied by hypothermia (temperature often 37.5 to 38.5°C) and an increased total white blood cell count (12×109 to 15×109/L). However, only less than half of the children present with typical signs and symptoms. The clinical picture is often atypical and the pain is sometimes not easily localized, especially in infants and children. Diffuse abdominal pressure or tenderness in the anterior rectal wall during rectal finger examination only; sometimes the child is asked to jump for pain in the right lower abdomen. In this case, the examination should be repeated, and if the child is uncooperative, the examination can be repeated after sleep or after the application of sedatives, which can improve the correct diagnosis rate. Diagnosis and treatment options 1. A clear diagnosis can be made with typical symptoms, signs and corresponding auxiliary examinations. However, in the early stage of appendicitis, X-ray, ultrasound and CT examination may not have positive findings; while in the middle and late stage, ultrasound and CT examination can help to diagnose enlarged appendix, abscesses, especially those in the pelvic and subdiaphragmatic regions, and laparoscopy is helpful for patients, both for diagnosis and differential diagnosis. Since appendiceal perforation can occur within 24 hours after the onset of symptoms, surgical treatment after the diagnosis of appendicitis is clear, i.e. appendectomy is the better choice to avoid appendiceal perforation and diffuse peritonitis. The surgery can be either open or minimally invasive (laparoscopic appendectomy). Obviously, minimally invasive surgery is less invasive, recovery is faster, intraoperative cleaning of pus is more thorough, and the chances of postoperative intestinal adhesions are significantly reduced. If conditions are available, try to choose minimally invasive surgery. 3.In some patients with a long history of disease, about 5 days or more, with peri-appendiceal abscess formation and serious adhesions and difficulties in separation, percutaneous puncture with catheter drainage under the guidance of ultrasound can be performed, or open surgery with drainage and anti-infection treatment can be performed first, and then appendectomy can be performed after 3-6 months. 4, intravenous antibiotics should be injected before surgery, and continue to use during the operation and the early postoperative period. The effect of using third generation cephalosporin is more certain. When acute appendicitis is suspected, conservative treatment with antibiotics alone should not be used if there is no contraindication, so as not to delay the disease. If the appendix is found to be normal during surgery, the distal small intestine within 2 meters from the ileocecal region should be examined to exclude Meckel’s diverticulum or ileitis (Crohn’s disease, etc.), while female children should be carefully examined for pelvic organs to detect ovarian cysts, tubal inflammation or ectopic pregnancy. In some patients, only mesenteric lymph node hyperplasia at the end of the ileum is seen. In patients with difficult localization of the appendix, the appendix is often located behind the cecum or ileum and within the mesentery of the right hemicolectum. Prognosis With early surgery, the mortality rate of acute appendicitis is very low or even zero, and patients are usually discharged within a few days. If the appendix is perforated, a limited abscess or diffuse peritonitis is formed, the prognosis is more serious and adhesive intestinal obstruction due to inflammation is common; antibiotics can significantly reduce the mortality rate, but conservative treatment often carries the risk of reoperation and prolonged recovery or even adhesive intestinal obstruction. Although it is still debated whether to perform surgery or conservative treatment against infection in acute appendicitis, surgical treatment is currently the mainstream with obvious advantages.