Intussusception is a condition in which a portion of the intestine and its ligaments become lodged in the adjacent intestine, causing obstruction to the passage of intestinal contents. The majority of intussusceptions are proximal intestine into the distal intestine, while reversible intussusceptions are rare and most common in infants under 2 years of age, especially in infants aged 4-10 months, and more common in spring. The typical symptoms of intussusception are tetralogy of Fallot, i.e. crying, vomiting, bloody stool and abdominal swelling. 1, crying: crying is the earliest and most important symptom of intussusception, and is a unique manifestation of abdominal pain in infants, characterized by sudden, violent, rhythmic crying. A healthy infant suddenly cries, pale, clenches fists, bends knees and shrinks abdomen, moves hands and feet, refuses food and milk, the attack lasts for 3-5 minutes and then relieves itself, and after an interval of 10-20 minutes, the attack resumes. Some children are better behaved and show paroxysmal pouting and arching of the back instead of crying. 2. Vomiting: Vomiting occurs soon after the crying episode, initially as milk, milk lumps and food residues, later as bile, and later as fecal-like liquid, indicating intestinal obstruction. 3, bloody stool: stool with blood is a characteristic manifestation of intestinal entrapment, blood in the stool mostly occurs 8-12 hours after the start of crying. Typical blood is red jam-like mucus blood stool, but also fresh blood stool or pus blood stool, and a few hours later can be repeated several times. 4, abdominal swelling: the swelling palpable in the abdomen is an overlapping intestinal tube. It is difficult for parents to feel the abdominal masses, but experienced pediatricians can feel the masses, and palpable abdominal masses are a meaningful diagnosis. In the late stage of the disease, the intestinal tube may reach the rectum, and occasionally the mass may prolapse from the anus.