Necrotizing Enterocolitis Overview

Necrotizing enterocolitis (NEC) is a condition where the intestines become infected and can begin to die. The disease usually affects premature babies, although term babies may also get NEC. Necrotizing enterocolitis is a serious condition that may require surgery and has a high morbidity and mortality rate.

Father touching head of a premature baby in a incubator at the Neonatal Intensive Care
Christian Wheatley / E+ / Getty Images 


The inner lining of the intestines contains millions of bacteria. Usually, these bacteria (called the normal flora) are harmless and are part of the digestive process.

In NEC, though, the bacteria begin to attack the intestinal wall. If the disease is not treated promptly, the intestinal wall will weaken and may die.

Eventually, a hole can form through the bowel wall (a perforation), spilling its contents into the abdominal cavity. Bowel perforation is a medical emergency that requires immediate surgery and has a high mortality rate.


Prematurity is the biggest risk factor for the development of NEC because preemies are born with immature intestines. Beyond that, physicians aren’t exactly sure what causes NEC. They know that the vast majority of infants who get NEC have begun milk feedings, but they also know that delaying feedings does not reduce the frequency of the disorder.

Reduced blood flow to the intestines may also play a factor in the development of necrotizing enterocolitis, and babies who have heart conditions such as a patent ductus arteriosis (PDA) are at higher risk for developing NEC.


In the early stages of NEC, the infection causes the movement of food and air through the intestines to slow down or stop. This causes the baby’s belly to look bloated or distended. After feedings, food will be left in the baby’s stomach as gastric residuals.

Eventually, enough food and air become trapped in the intestines that bowel loops will be visible on the baby’s belly. The belly will become painful and discolored, and the baby may begin vomiting bile or having bile-tinged residuals.

Blood may be present in the baby’s stools, and the baby may begin to be bloated all over and have less urine output. The baby may also have a hard time regulating his temperature and may begin to have spells of apnea or bradycardia.

Eventually, the bowel will rupture, causing widespread infection and respiratory distress.


In the early stages, treatments for NEC include stopping milk feedings to let the bowel rest, giving antibiotics to treat infection, and removing air from the stomach. The baby will receive frequent X-rays to watch the disease’s progress.

If medical treatment is not working or if the bowel perforates, surgery is required. A surgeon will remove any dead sections of bowel and other infected material. The bowel will either be reattached or will be diverted to the abdomen through a stoma. Medical treatments will continue until the disease is resolved.


NEC is a serious disease, and infants who recover from NEC are at a greater risk of developing long-term problems. Infants who are medically treated for NEC may have growth delays, trouble absorbing nutrients, and trouble with their livers and gall bladders. NEC also increases the risk of developmental delays.

Infants who have had surgery for NEC also show long-term effects from the disease. In addition to the effects of medical NEC, surgical patients may have severe absorption problems such as short bowel syndrome and have an increased risk of cerebral palsy and brain and eye problems.


Preventing premature birth is the best way to prevent necrotizing enterocolitis. If you are at risk for preterm birth, talk with your physician about what you can do to lower your risk.

If preterm birth does occur, then feeding only breast milk can significantly lower the risk of NEC. Breast milk contains protective factors that encourage good intestinal development and can reduce the amount of harmful bacteria in the intestines. In one study, infants whose feedings contained at least 50% breast milk had a six-fold decrease in the incidence of NEC.

In addition to preventing preterm birth and feeding breast milk, giving steroids to the mother when premature birth is expected may reduce the risk of NEC. Also, supplementing breast milk and formula with different substances such as probiotics or immunoglobulins may help, although more research is needed.

12 Sources
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Additional Reading
  • Bradshaw, MSN RN NNP-BC, CCRN Wanda Todd. “Necrotizing Enterocolitis: Etiology, Presentation, Management, and Outcomes.” The Journal of Perinatal & Neonatal Nursing 23:87-94.

  • Schurr, P and Perkins, EM. “The Relationship Between Feeding and Necrotizing Enterocolitis in Very Low Birth Weight Infants.” Neonatal Network 27:397-407.