Acquired Disorders of the Gastrointestinal Tract Necrotizing enterocolitis (NEC) most common gastrointestinal (GI) emergency in premature infants □ Clinical features □ Incidence, ∼12% of infants born at <1500 g, 30% mortality □ Postnatal age of onset and incidence inversely related to birth weight and gestational age □ 90% of infants with NEC premature □ Term, late preterm infants infrequently develop NEC; risk factors (associated with bowel ischemia) include intrauterine growth restriction (IUGR) and small for gestational age (SGA), birth asphyxia, congenital heart disease, gastroschisis, polycythemia, hypoglycemia, sepsis, exchange transfusion, ± umbilical lines □ Can occur in epidemics □ Occurs more frequently in African-American infants than white infants □ More common following initiation of enteral feeds □ Breast milk and established feeding guidelines—protective factors □ 50% require surgery