Necrotizing enterocolitis (NEC) is a devastating disease of premature infants, with a mortality rate of 10-50%. It is uncommon in term infants and in premature infants who have not yet been fed. Most commonly NEC develops suddenly in a preterm infant who was otherwise well, with initial symptoms of abdominal distention, bilious or bloody emesis or gastric aspirates, hematochezia, and pneumatosis intestinalis, and sometimes progresses quickly to include bowel perforation, acidosis, shock, and death. Trigger factors (i.e. perinatal hypoxia, mild infection or formula feeding) cause focal mild intestinal mucosal injury. In the presence of proliferation of commensal bacteria, local breakdown of mucosal barrier may cause entry of bacterial products (e.g. lipopolysaccharides, platelet-activating factor). Endothelial platelet-activating factor and/or tumor necrotizing factor and/or direct stimulating effects of polymorphonuclear leukocytes cause proinflammatory cascade and focal necrosis, which increase the entry of large amounts of bacterial toxins, and then severe NEC, sepsis, and shock develop. Therapies for the prevention of NEC that appear to have some benefit are breastfeeding and antenatal steroids, and probably probiotics. Enteral immunoglobulin, polyunsaturated fatty acids, and arginine or glutamine supplementation are therapies for the prevention of NEC that do not appear to be of benefit. Enteral erythropoietin and enteral granulocyte colony-stimulating factor are promising novel therapies. Treatment options are limited to gut rest, parenteral nutrition, broad-spectrum antibiotics, and surgical interventions for enteral perforation. Two commonly used methods for NEC with intestinal perforation are laparotomy or primary peritoneal drainage ("patch, drain and wait"); however, the preferred method is controversial.