Necrotizing Enterocolitis: Causes, Symptoms And Treatment

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Necrotizing enterocolitis or NEC is a fatal condition that affects premature infants or newborns. The most common neonatal emergency in the US, NEC may seem like any other gastrointestinal infection but is a serious illness that can eventually destroy the wall of the intestine.

Read this Momjunction post to know more about necrotizing enterocolitis in neonates, its causes, treatment options, and complications.

What Is Necrotizing Enterocolitis?

Necrotizing enterocolitis is a gastrointestinal disease in which a section of the small or large intestine suffers cell damage (necrosis) and death (1). It leads to severe inflammation of the bowel, and its inability to process ingested food. The name is derived from three words (2):

  • “Necrotizing”, meaning damaged and dead
  • “Entero”, which refers to the intestine and
  • “Colitis”, meaning the inflammation of the colon, which is the lower section of the intestine

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How Common Is Necrotizing Enterocolitis?

NEC occurs in one out of every 2,000-4,000 births (1).

  • It is most common among premature babies with a birth weight less than 4.5lb (2kg). Babies weighing less than 3.3lb (1.5kg) are the ones at maximum risk of this condition.
  • Nearly 10% of babies weighing less than 3.3lb (1.5kg) eventually develop necrotizing enterocolitis (3).
  • 80% of cases diagnosed involve premature infants.

NEC is rare among infants born with healthy body weight and in older infants.

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[ Read: Intussusception In Babies ]

What Causes Necrotizing Enterocolitis?

The exact cause of necrotizing enterocolitis in babies is not known (3). Experts, however, suspect that reduced blood supply to the intestines makes them prone to the proliferation of bacteria found in the ingested food, leading to NEC. Babies with a low blood oxygen level due to any other condition are at risk as well. These factors can make the bacteria in milk and formula potential pathogens that cause NEC in infants.

Inflammation due to NEC increases the risk of perforation in the intestines. Bacteria move out through the holes and invade other organs of the abdomen, spreading the infection. Several bacteria can cause NEC, but the notable ones are E.coli, Clostridium, Klebsiella, and Staphylococcus (4).

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What Are The Risk Factors Of Developing Necrotizing Enterocolitis?

Some conditions or situations can make a baby more susceptible to the development of NEC:

  • Preterm birth: Premature babies have partially developed gastrointestinal tract, blood supply, and poor immunity, which increases their chances of developing infections.
  • Congenital disorders: Having a congenital disorder such as congenital heart problems, respiratory distress, and hypoglycemia could also put the child at risk of NEC. These conditions usually cause a drop in the blood oxygen, which increases the risk of NEC.
  • Infections early in infancy: Developing infections, especially gastrointestinal infections, early in infancy can increase the chances of the baby getting necrotizing enterocolitis. Development of sepsis, a severe complication of an infection, wherby infection spreads to all organs, also increases the risk.
  • Maternal infections: If the mother suffered severe fetal infections during gestation, then the baby is at risk of getting NEC after birth. An example is amnionitis, a disease of the amniotic sac that can also spread to the fetus.
  • Low oxygen levels: Low levels of oxygen in the blood due to congenital problems respiratory disease, heart problems, or other issues.
  • Problems during birth: Babies who do not get sufficient oxygen at birth could have low blood oxygen levels, which puts them at the risk of NEC. Prolonged delivery, a complication with the umbilical cord and birth asphyxia, a condition where the baby does not get sufficient oxygen during the birth process, are a few problems during delivery that could increase the risk of NEC.

Treating NEC in time is vital for the safety of the child. Read on to learn more about the symptoms you should look for diagnosing NEC early.

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[ Read: Causes Of Blood In Baby Stool ]

What Are The Symptoms Of Necrotizing Enterocolitis?

Symptoms of NEC in a baby include (5):

  1. Bloating and swelling of the stomach, which is also called abdominal distention in medical terms. The baby will also have pain in the stomach, and the belly would get painful and tense on touch.
  1. Retention of food in the stomach and intestine, which means the food does not get absorbed, digested or come out as stools.
  1. If the baby does have stools, they are diarrhoea like, mucoid and will contain red  blood or blood clots.
  1. Vomiting is common. Watery green coloured vomitus. The expelled contents would be greenish due to the presence of bile.
  1. Irregular breathing rate and respiratory distress. Difficulty in breathing.Pause in breathing may also occur, which is called apnea.
  1. Fluctuating fever, lethargy, apathy, irritability fussiness, and colic.

These symptoms usually appear 8-14 days after birth. In the case of extremely premature babies, symptoms may emerge much later. NEC develops only after the initiation of the first feed, which in the case of preterm infants would be through a tube that goes straight into the stomach.

Premature babies in the neonatal intensive care unit are diagnosed sooner as their symptoms are detected by the doctors early on. If your baby is full term and shows signs of NEC, go to the doctor right away.

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How Is Necrotizing Enterocolitis Diagnosed?

A regular X-ray can help diagnose NEC in babies. The doctor will check for the bubble-like appearance of the intestine and the swollen veins of the liver on the X-ray. The intestine, as well as the abdomen, will also contain large gas shadows, fluid levels released inside the intestine by the bacteria, which can be detected through an X-ray.

The extent of the infection

NEC diagnosis can be categorized into three stages depending on the extent of the infection and the symptoms displayed (5).

  • Stage 1 – Suspected NEC: The baby would display non-specific or general symptoms that could indicate necrotizing enterocolitis. Symptoms include lethargy, fussiness, and fever. An X-ray in this stage displays abdominal distention or gastric residues but not the extent to prove it to be NEC.
  • Stage 2 – Proven NEC: X-rays show clear signs of NEC with the presence of large gas globules, fluid levels within the intestine. Bowel sounds will be absent due to a dysfunctional intestine.
  • Stage 3 – Advanced NEC: The intestine is damaged to the extent that there are holes in the intestinal wall. The baby also has severe sleep apnea, low blood pressure, and inflammation of the entire abdominal wall.

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[ Read: How To Prevent UTI In Babies ]

How Is Necrotizing Enterocolitis Treated?

Babies with NEC have to be admitted to the hospital for treatment. The doctor will take into account the baby’s age, health, stage of NEC, and tolerance to different medicines before initiating treatment. Treatment involves the following steps and methods (4):

  • Keep the baby NPO (Nothing per Orally). Stop feeding to keep the stomach empty. The baby will get the necessary fluids and nutrients intravenously.
  • A nasogastric tube inserted from the nose to the stomach allows for suctioning out the fluid, blood, discharges, bile formed in the intestine. It relieves swelling, bloating, and helps baby heal better.
  • An antibiotic course, often given intravenously.
  • In extreme cases, the baby is kept on a ventilator to ensure that the lungs and the blood get adequate oxygen.
  • Surgery is needed only in severe cases of NEC. The pediatric surgeon removes the infected section of the bowel and stitches the rest of the gastrointestinal tract together. Surgeons aim at removing as little of the colon as possible and retain the most. If the intestine seems healthy and can survive the infection, then surgeons only remove gas and drain out the fluids from the gastrointestinal tract.

Less than 25% of infants need surgery, while the rest are resolved through supportive care and antibiotic therapy (4). The duration of treatment and rate of recovery varies in each patient, and it could take weeks to several months for the baby’s gastrointestinal tract to become normal.

The baby may have to be monitored throughout childhood to prevent the onset of other infections and complications associated with NEC. Your doctor may provide specific feeding and care guidelines for the baby. Timely treatment, along with aftercare, is necessary to prevent any complications of NEC.

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What Are The Complications Of Necrotizing Enterocolitis?

Untreated NEC can lead to the following problems:

  • Spread of infection: When left untreated for long, the bacteria from the intestine can spread to the other parts of the body through the bloodstream including lungs, kidneys, and brain. Widespread infection of organs and its related immune response can cause a fatal disease called sepsis.
  • Metabolic problems: Since the intestine does not function correctly, the body cannot absorb food properly. It can lead to conditions such as hypoglycemia, which is chronic low blood sugar. NEC could also lead to increased acidity of the blood, a metabolic problem that can damage kidneys.
  • Multiple blood clots: Internal bleeding due to NEC can cause blood clots that could block small blood vessels. Such a condition is called disseminated intravascular coagulation. This may result in haemhorrages and bleeding.
  • Respiratory and cardiovascular problems: The baby is also at risk of developing problems with the heart and lungs due to hypotension and respiratory failure when the body does not get enough oxygen from the lungs.

Specific measures can minimize the risk of NEC, and in some cases, maybe even prevent it.

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[ Read: How To Relieve Stomach Pain In Babies ]

How To Prevent Necrotizing Enterocolitis?

There is no precise prevention for necrotizing enterocolitis since its cause is not apparent. However, you can take precautions after consulting with the doctor if your baby falls into the high-risk category. Here is what you can do to reduce the risk of NEC in your baby:

  • Breast milk: Pediatric experts note that babies who have only breast milk are not so much at risk of NEC Premature babies who are given food through tubes (enteral feeding) should be given expressed milk to minimize NEC risk. Breast milk is also beneficial for low birth weight infants. A study has found that providing low birth-weight babies a feed consisting of at least 50% breast milk in the first 14 days after birth reduces the risk of NEC by six times (6).
  • Delaying feed: Feeding through the mouth can be delayed in the case of premature babies whose gastrointestinal tract is still underdeveloped and immature. You can consider it after doctor’s consultation. In any case, your infant would be in intensive care at the hospital, which might delay oral feeding anyway.
  • Probiotics: Probiotic bacteria such as Bifidus infantis and Lactobacillus acidophilus can help reduce the risk. But there is limited research on their efficacy, the precise dosage, and the type of bacteria that works. Consult your doctor before adopting this measure.

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Necrotizing enterocolitis is a dangerous disease. While the disease holds the risk of mortality, it rarely happens, and 70-75% of infants survive the condition. Better medicines and supportive care have improved the survival rates of infants with this disease. Keeping an eye on the baby’s health especially during the first six months, and exclusive breastfeeding are the best steps to keep necrotizing enterocolitis at bay.


1. Necrotizing Enterocolitis Symptoms And Treatment; UPMC, Children’s Hospital of Pittsburgh
2. Necrotizing Enterocolitis; The Children’s Hospital of Philadelphia
3. Reviewed by D. Freeborn, K. Lee; Necrotizing Enterocolitis in the Newborn; University of Rochester Medical Center
4. W J Cochran; Necrotizing Enterocolitis; Merck Manuals (2017)
5. Necrotizing Enterocolitis; The University of Chicago, Pediatrics Clerkship
6. P M Sisk, C A Lovelady et al.; Early human milk feeding is associated with a lower risk of necrotizing enterocolitis in very low birth weight infants; Journal of Perinatology (2007)

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