What Is Necrotizing Enterocolitis?

Medically Reviewed by Amita Shroff, MD on December 02, 2022
4 min read

Necrotizing enterocolitis, or NEC, is a serious disease that affects the intestines of (primarily)  premature infants. It typically happens within the first 2 weeks of life in babies who are fed formula instead of breast milk.

In this condition, bacteria invade the wall of the intestine. Inflammation sets in. This can create a crack or gap that allows nasty germs to leak into the abdomen. If not treated, it can lead to serious infection and death.

Doctors aren’t sure. They do know that premature infants have lungs and intestines that are weak and less mature than those of full-term babies. That means their bodies don’t move blood and oxygen around like they should. They also have problems breaking down their food and fighting infection.

Fortunately, NEC is not common. It affects just one in 2,000 to 4,000 births. It can happen in any newborn, but it’s most common in premature babies who weigh less than 3.25 lbs. Others who may be at risk include:

  • High-risk or premature babies who are fed formula by mouth or tube
  • Those who had a difficult delivery or have lowered oxygen levels
  • Infants who have too many red blood cells in circulation
  • Babies with existing gastrointestinal infections
  • Seriously ill infants and those who’ve received a blood transfusion

They can differ from child to child. But an infant who has NEC will normally develop the following in the first two weeks of life:

Other digestive conditions or medical problems produce similar symptoms to NEC. If your child develops any of those listed above, call your doctor.

Your child’s doctor will take an X-ray of their abdomen and do some blood tests, usually in the neonatal intensive care unit. If it’s NEC, the X-ray will show gas or air bubbles in the wall of their intestine. Blood tests for infants with NEC show low white blood counts. That means your baby’s ability to fight infection is weakened.

This will depend on a number of things, including how premature your baby is, their overall health and medical history, and how far the infection has spread.

Then, your doctor may do any of these things:

  • Stop feedings
  • Insert a tube through their nose and into their stomach to remove fluid and keep their stomach empty.
  • Start IV fluids to keep them nourished and hydrated
  • Give antibiotics to fight infection
  • Take regular X-rays to monitor the condition
  • Provide extra oxygen or a breathing machine if their belly is too swollen for them to breathe on their own
  • Keep them away from other babies to stop the spread of NEC

Once the infection is gone (typically in 5 to 7 days), your baby can start feeding again by mouth.

If they don’t get better with treatment or they have a hole in their intestine, they’ll need surgery. This involves removing dead tissue and the parts of the intestine that have ruptured or are about to rupture. In the most serious cases, children who have surgery may need to have their intestine or bowel connected to an opening in the abdomen. Doctors call this an “ostomy.”

Most infants with this condition fully recover. In some cases, the bowel is scarred or it narrows. This may lead to a future blockage. Babies who’ve had a large piece of their intestine removed in surgery may not be able to absorb nutrients normally. In the most severe cases, they may need a bowel transplant in order to live.

Right now, there’s no way to prevent NEC. But studies show that babies who were only fed breast milk (no formula), were less likely to develop this disease. That’s why doctors recommend feeding at-risk infants breast milk, starting with small amounts. Many NICU's are now using donor breast milk when there is none available from the mother in order to reduce the incidence of NEC

Researchers are working on promising new treatments for NEC. Among them: probiotics, which are live bacteria and yeasts that are good for you, to counteract the bacteria that cause the infection, and blocking nitric oxide. That’s a gas which is produced as a result of NEC. It helps to destroy the wall of the intestine.