Intussusception is a segment of the intestine that becomes lodged in the lumen of the intestine to which it is attached and causes obstruction to the passage of the intestinal contents. Acute intussusception is common in clinical practice, while chronic intussusception is usually secondary. Acute intussusception is most often seen in infancy, with infants aged 4 to 10 months being the most common, and the incidence decreasing with age after 2 years. Intussusception can occur throughout the year, with the highest incidence in late spring and early summer, and may be related to upper respiratory tract infections and viral infections. The incidence is high in China, accounting for the first place of intestinal obstruction in infants. 1, acute intussusception The cause is still unclear, may be related to the following factors: (1) dietary changes: 4 to 10 months after birth, for the addition of complementary foods and increase the amount of milk period, is also the peak of intussusception. Since the infant’s intestine cannot immediately adapt to the stimulation of the changed food, it leads to intestinal dysfunction and causes intussusception. (2) Ileal anatomical factors: the ileal part of the infant is mobile, the ileal flap is overly hypertrophic, the small intestinal tract is relatively long, 90% of the infant ileal flap is lip-like convex into the cecum, up to 1 cm or more, coupled with the rich lymphoid tissue in this area, inflammation or food stimulation is easy to cause congestion, edema, hypertrophy, intestinal peristalsis is easy to push the ileal flap forward, and pull the intestinal tube to form a ligature. (3) Viral infections: A series of studies reported that acute intussusception is related to adenovirus and rotavirus infections in the intestine. (4) Intestinal spasm and autonomic dysregulation: Intestinal spasm is caused by various foods, inflammation, diarrhea, bacterial toxins, etc., which stimulate the intestine to produce spasm and cause intestinal peristaltic rhythm disorder or retroperistalsis. (5) Genetic factors: some patients with intestinal entrapment have a family history of morbidity. (6) congenital intestinal malformation and other organic diseases: such as Merkel’s diverticulum, congenital intestinal duplication malformation, etc. can become the cause of acute intussusception. 2, chronic recurrent intussusception Most commonly seen in older children and adults, the cause of its occurrence is often secondary to the presence of intestinal gas-type lesions caused by secondary intussusception, intestinal organism lesions commonly have intestinal polyps, diverticula, repetitive malformations, purpura hematoma, tumors and tuberculosis. Intussusception is a common acute abdominal condition in pediatric patients, and the pathological cause is mostly small intestine overlapping into large intestine, but also small intestine overlapping into small intestine or large intestine overlapping into large intestine. The symptoms are usually paroxysmal crying, vomiting, refusal of milk, or bloody stools if sauce-like, usually without fever. The causes are mostly diarrhea, enlarged mesenteric lymph nodes, weaning or congenital intestinal malformation. Once the above symptoms appear in children, parents should be alert to the possibility of intussusception, it is best to immediately go to the hospital, experienced doctors through abdominal palpation or ultrasound CT, can clarify the presence of intussusception. Once the diagnosis is confirmed, air enema is usually first, that is, through the anal tube to inject high-pressure air into the colon, through the air pressure to make the set into the intestinal tube back to normal. If the onset of intussusception is too long, the enema fails or there is a lot of bleeding in the intestine, then surgery is required. Intussusception occurs suddenly, if parents have common knowledge of the disease, timely diagnosis and treatment, the prognosis is good; if delayed treatment, the occurrence of intestinal necrosis and other serious complications, the child’s prognosis is poor, or even death!