Definition and Overview

Necrotising enterocolitis (NEC) is a serious gastrointestinal tract (GI) disease that commonly occurs in premature babies. It causes damage and death of intestinal tissue. As a result, the intestine swells and becomes perforated. This can cause the waste from the colon to leak into the abdominal cavity. The bacteria that help digest food in the GI tract can also leak into the bloodstream. This increases the risk of sepsis.

What causes NEC to occur is unknown. But having an underdeveloped intestine is a huge risk factor. While some patients are able to fully recover with prompt treatment, many babies do not survive. NEC is one of the most common causes of deaths in premature babies. The most vulnerable are infants born less than 1,500g or 3.3 lbs.

Causes of Condition

Doctors do not know exactly what causes NEC. But several factors have been proven to play a role. The biggest one is being born prematurely. Up to 90% of NEC cases involve premature babies. They are more prone to the disease because their intestines are not yet fully developed. This makes their intestines too weak to fight infections. NEC can also occur if blood and oxygen supply to the digestive system is reduced or cut off during a difficult delivery.

Other possible causes are:

  • Injury to the intestines.

  • Having other GI disorders and too many red blood cells in the GI tract.

  • Formula feeding - NEC is more common in formula-fed babies than those who are breastfed. More studies are being done to confirm the link between formula feeding and NEC.

  • Spread of infection - There have been cases wherein infants in the same nursery had NEC. This suggests that it could be possible for the disease to spread from one baby to another.

Key Symptoms

Symptoms of NEC begins to show when the baby is about two to four weeks old. Parents may notice that their babies are not eating as well as before. Their belly may also be swollen or bloated. This occurs when their intestine starts to swell.

Problems with the intestines can cause changes in bowel movements. The patient may become constipated or pass bloody stool. Other signs include a low body temperature and green vomit.

Unless treated promptly, the patient can quickly become very sick. Signs that the disease is progressing are:

  • Apneoa - A disorder marked by breathing pauses that last between a few seconds and minutes during sleep. It reduces the baby’s oxygen supply. This can make NEC even worse.

  • Ascites, or the build up of fluid in the abdomen. This can cause infection and kidney failure. It can also lead to malnutrition and weight loss.

  • Hypotension, or low blood pressure.

  • Peritonitis, or the swelling of the thin layer of tissue inside the abdomen.

  • Shock - In most severe cases, patients can go into shock. This can be caused by severe infection.

Who to See and Types of Treatments Available

To diagnose NEC, a doctor will:

  • Check the abdomen for swelling.

  • Check for any signs of inflammation.

  • Measure the baby’s platelets levels as well as white blood cell counts.

  • Confirm the presence of bacteria in the patient’s blood.

  • Check for ascites or fluid build up in the abdomen.

Once diagnosed, treatment is started right away. The doctor will:

  • Treat the infection using antibiotics.

  • Drain fluid from the abdominal cavity.

  • Stop all feedings. The baby will receive intravenous fluids for nutrition. This gives the damaged part of the intestine the time it needs to heal.

  • Put the baby on a ventilator if he or she is not breathing properly.

Surgery is used if patients do not respond well to the above treatments. Surgery allows doctors to check the abdominal cavity more closely. This helps them assess the severity and extent of damage. Dead tissues can be removed during the same surgery. The parts of the intestine with holes are also repaired. The remaining healthy parts are then sewn back together.

Surgeons can also divert the flow of faeces from the colon and anus. This gives the damaged intestines enough time to heal. Doctors do this by bringing a part of the intestine to an opening in the abdomen (stoma). The stoma can be temporary or permanent.

After surgery, babies are transferred to the neonatal intensive care unit (NICU). Here, they receive the high level of care they need to get better. Many babies have to stay in the hospital for weeks or even months. Their stay can be longer if they have other health issues.

The prognosis for NEC patients depends on many factors. The disease can be deadly for babies who are very small. It can also be deadly if patients are not treated right away. However, many are able to fully recover after treatment. Many also do not have lasting medical problems. Others, on the other hand, can suffer from chronic malabsorption. This means that they do not receive enough nutrients from the food they eat. This can occur in babies who had parts of their intestines removed.


  • Luig M, Lui K NSW ACT NICUS Group. Epidemiology of necrotizing enterocolitis—part II: risks and susceptibility of premature infants during the surfactant era: a regional study. J Paediatr Child Health. 2005;41(4):174–179.

  • Stout G, Lambert DK, Baer VL, et al. Necrotizing enterocolitis during the first week of life: a multicentered case-control and cohort comparison study. J Perinatol. 2008;28(8):556–560.

  • Kamoji VM, Dorling JS, Manktelow B, Draper ES, Field DJ. Antenatal umbilical Doppler abnormalities: an independent risk factor for early onset neonatal necrotizing enterocolitis in premature infants. Acta Paediatr. 2008;97(3):327–331.

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