(Necrotizing Enterocolitis)

Necrotizing enterocolitis (NEC) is a disease that affects mostly the intestines of premature infants. The wall of the intestine is invaded by bacteria, which cause local infection and inflammation that can ultimately destroy the wall of the bowel (intestine). Such bowel wall destruction can lead to perforation of the intestine and spillage of stool into the infant’s abdomen, which can result in an overwhelming infection and death. 

Overall, NEC affects one in 2,000 to 4,000 births (approx. 9000 infants a year), or between one percent and five percent of neonatal intensive care unit admissions. The disease occurs in nearly 10 percent of premature infants but is rare in full term infants. Although the exact cause of NEC is still unknown, there are many theories to explain why NEC mainly affects premature infants.

The only consistent observations made in infants who develop NEC are the presence of prematurity and formula feeding. The premature infant has immature lungs and immature intestines. Therefore, any decrease in oxygen delivery to the intestines, because the lungs cannot oxygenate the blood adequately, will damage the lining of the intestinal wall. This damage to the bowel wall will allow bacteria that normally live inside the intestine to invade the wall of the intestine and cause local infection and inflammation (NEC) that can eventually lead to rupture or perforation of the intestine.