Elsevier created a COVID-19 resource centre in January 2020, offering free information on the virus in English and Mandarin. The centre is hosted on Elsevier Connect, and the company grants permission for free access to its research in PubMed Central and other repositories for unrestricted reuse. Necrotizing enterocolitis (NEC) is a severe gastrointestinal disorder in neonatal intensive care units (NICUs), characterized by signs of sepsis and various gastrointestinal disturbances. Its incidence varies widely, with a typical rate of 1-5% among NICU admissions. The mortality rate ranges from 0 to 55.5%, with a 40% mortality rate in a 1976 study. NEC is a major perinatal public health concern due to its high mortality and morbidity in neonates. Despite extensive research, the exact causes remain unclear. NEC is often seen in preterm infants and develops during their NICU stay. Risk factors include prematurity, polycythemia, and other neonatal issues. Many infants with NEC have no identifiable risk factors. NEC can be classified as endemic or epidemic, with epidemics showing higher birthweights and later onset compared to endemic cases. NEC presents with a wide range of clinical manifestations, including signs of feeding intolerance and symptoms similar to neonatal sepsis. Diagnosis is suspected when typical gastrointestinal signs are present, and confirmed with radiographic findings such as pneumatosis intestinalis or intrahepatic portal venous gas. Other diagnostic methods include echocardiography, ultrasonography, and breath hydrogen excretion. Staging of NEC is based on clinical manifestations, with stages ranging from mild to severe. Stage I includes infants with mild symptoms, while Stage III involves severe disease with shock and intestinal perforation. Treatment is based on the severity of the disease, with bowel rest, antibiotics, and surgical intervention for perforation. The pathogenesis of NEC is not fully understood, but factors such as gastrointestinal immaturity, enteral feeding, and bacterial infection are implicated. Bacteria, particularly clostridia, may contribute to NEC, especially in cases of malabsorption or ischemia. The role of milk protein allergy and bacterial toxins is also considered. Treatment of NEC involves prompt recognition, aggressive monitoring, and early intervention. Patients with Stage I or suspected NEC may benefit from bowel rest and antibiotic therapy. Stage III NEC requires longer treatment, including intravenous antibiotics and fluid resuscitation. Surgery is indicated for intestinal perforation. Long-term outcomes for survivors of NEC vary, with some developing complications such as intestinal strictures or bacterial sepsis. However, long-term growth and neurodevelopment are generally encouraging. Future research aims to better understand the etiology of NEC and improve treatment strategies.Elsevier created a COVID-19 resource centre in January 2020, offering free information on the virus in English and Mandarin. The centre is hosted on Elsevier Connect, and the company grants permission for free access to its research in PubMed Central and other repositories for unrestricted reuse. Necrotizing enterocolitis (NEC) is a severe gastrointestinal disorder in neonatal intensive care units (NICUs), characterized by signs of sepsis and various gastrointestinal disturbances. Its incidence varies widely, with a typical rate of 1-5% among NICU admissions. The mortality rate ranges from 0 to 55.5%, with a 40% mortality rate in a 1976 study. NEC is a major perinatal public health concern due to its high mortality and morbidity in neonates. Despite extensive research, the exact causes remain unclear. NEC is often seen in preterm infants and develops during their NICU stay. Risk factors include prematurity, polycythemia, and other neonatal issues. Many infants with NEC have no identifiable risk factors. NEC can be classified as endemic or epidemic, with epidemics showing higher birthweights and later onset compared to endemic cases. NEC presents with a wide range of clinical manifestations, including signs of feeding intolerance and symptoms similar to neonatal sepsis. Diagnosis is suspected when typical gastrointestinal signs are present, and confirmed with radiographic findings such as pneumatosis intestinalis or intrahepatic portal venous gas. Other diagnostic methods include echocardiography, ultrasonography, and breath hydrogen excretion. Staging of NEC is based on clinical manifestations, with stages ranging from mild to severe. Stage I includes infants with mild symptoms, while Stage III involves severe disease with shock and intestinal perforation. Treatment is based on the severity of the disease, with bowel rest, antibiotics, and surgical intervention for perforation. The pathogenesis of NEC is not fully understood, but factors such as gastrointestinal immaturity, enteral feeding, and bacterial infection are implicated. Bacteria, particularly clostridia, may contribute to NEC, especially in cases of malabsorption or ischemia. The role of milk protein allergy and bacterial toxins is also considered. Treatment of NEC involves prompt recognition, aggressive monitoring, and early intervention. Patients with Stage I or suspected NEC may benefit from bowel rest and antibiotic therapy. Stage III NEC requires longer treatment, including intravenous antibiotics and fluid resuscitation. Surgery is indicated for intestinal perforation. Long-term outcomes for survivors of NEC vary, with some developing complications such as intestinal strictures or bacterial sepsis. However, long-term growth and neurodevelopment are generally encouraging. Future research aims to better understand the etiology of NEC and improve treatment strategies.