NEC is the abbreviation of neonatal necrotizing small intestinal colitis, which is very common in newborns belonging to preterm infants. Because the intestinal tract of preterm infants is immature, the main manifestations are less gastric acid secretion and poorer digestive enzymes, which can cause intestinal infections and ischemia of the intestinal wall, resulting in intestinal damage. Some newborns may also become worse after ischemia and hypoxia, such as after sepsis or enterocolitis, and are more likely to suffer from neonatal necrotizing small intestinal colitis. After necrotizing colitis, fasting, intravenous nutrition, gastrointestinal decompression, and adequate doses of antibiotics, such as third-generation cephalosporins, should be administered promptly.