Necrotizing enterocolitis
Necrotizing enterocolitis (NEC) is the death of tissue in the intestine. It occurs most often in premature or sick babies.
Premature or sick babies
A premature infant is a baby born before 37 full weeks of gestation (more than 3 weeks before the due date).
Causes
NEC occurs when the lining of the intestinal wall dies. This problem nearly always develops in an infant who is ill or premature. It is likely to occur while the infant is still in the hospital.
The exact cause of this disorder is unknown. A drop in blood flow to the bowel can damage the tissue. Bacteria in the intestine may also add to the problem. Also, premature infants have an undeveloped immune response to factors such as bacteria or low blood flow. An imbalance in immune regulation appears to be involved in NEC.
Babies at higher risk for the condition include:
- Premature infants
- Infants who are fed formula rather than human milk. (Human milk contains growth factors, antibodies, and immune cells which may help prevent the problem.)
- Infants in a nursery where an outbreak has occurred
- Infants who have received blood exchange transfusions or have been seriously ill
Symptoms
Symptoms may come on slowly or suddenly, and may include:
- Abdominal bloating
Abdominal bloating
A swollen abdomen is when your belly area is bigger than usual.
ImageRead Article Now Book Mark Article - Blood in the stool
Blood in the stool
Black or tarry stools with a foul smell are a sign of a problem in the upper digestive tract. It most often indicates that there is bleeding in the ...
ImageRead Article Now Book Mark Article - Diarrhea
Diarrhea
Normal baby stools are soft and loose. Newborns have stools often, sometimes with every feeding. For these reasons, you may have trouble knowing wh...
Read Article Now Book Mark Article - Feeding problems
- Lack of energy
Lack of energy
Fatigue is a feeling of weariness, tiredness, or lack of energy.
ImageRead Article Now Book Mark Article - Unstable body temperature
- Unstable breathing, heart rate, or blood pressure
- Vomiting
Exams and Tests
Tests may include:
- Abdominal x-ray
Abdominal x-ray
An abdominal x-ray is an imaging test to look at organs and structures in the abdomen. Organs include the liver, spleen, stomach, and intestines. T...
ImageRead Article Now Book Mark Article - Stool for occult blood test
Occult blood test
The stool guaiac test looks for hidden (occult) blood in a stool sample. It can find blood even if you cannot see it yourself. It is a common type ...
ImageRead Article Now Book Mark Article - Complete blood count (CBC)
Complete blood count
A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...
ImageRead Article Now Book Mark Article - Electrolyte levels, blood gases and other blood tests
Treatment
Treatment for a baby who may have NEC most often includes:
- Halting enteral (GI tract) feedings
- Relieving gas in the bowel by inserting a tube in the stomach
- Giving intravenous (IV or into a vein) fluids and nutrition
IV
Intravenous means "within a vein. " Most often it refers to giving medicines or fluids through a needle or tube inserted into a vein. This allows th...
Read Article Now Book Mark Article - Giving IV antibiotics
- Monitoring the condition with abdominal x-rays, blood tests, and measurement of blood gases
The infant will need surgery if there is a hole in the intestines or inflammation of the abdominal wall (peritonitis).
In this surgery, the surgeon will:
- Remove dead bowel tissue
- Perform a colostomy or ileostomy
Colostomy
Colostomy is a surgical procedure that brings one end of the large intestine out through an opening (stoma) made in the abdominal wall. Stools movin...
ImageRead Article Now Book Mark ArticleIleostomy
Small bowel resection is surgery to remove a part of your small bowel. It is done when part of your small bowel is blocked or diseased. The small bo...
ImageRead Article Now Book Mark Article
The bowel may be reconnected after several weeks or months when the infection has healed.
Outlook (Prognosis)
NEC is a serious disease. Up to 40% of infants with NEC die from it. Early, aggressive treatment can help improve the outcome.
Possible Complications
Complications may include:
- Peritonitis
Peritonitis
Peritonitis is an inflammation (irritation) of the peritoneum. This is the thin tissue that lines the inner wall of the abdomen and covers most of t...
ImageRead Article Now Book Mark Article - Sepsis
Sepsis
Sepsis is an illness in which the body has a severe, inflammatory response to bacteria or other germs.
ImageRead Article Now Book Mark Article - Intestinal perforation
Intestinal perforation
A perforation is a hole that develops through the wall of a body organ. This problem may occur in the esophagus, stomach, small intestine, large int...
ImageRead Article Now Book Mark Article - Intestinal stricture
Intestinal stricture
Intestinal obstruction is a partial or complete blockage of the bowel. The contents of the intestine cannot pass through it.
ImageRead Article Now Book Mark Article - Liver problems from prolonged inability to tolerate enteral feeds and need for parenteral (IV) nutrition
- Short bowel syndrome if a large amount of intestine is lost
When to Contact a Medical Professional
Get emergency medical care if any symptoms of necrotizing enterocolitis develop. Infants who are hospitalized for illness or prematurity are at higher risk for NEC. They are watched closely for this problem before they are sent home.
References
de la Cruz D, Neu J. Neonatal necrotizing enterocolitis. In: Martin RJ, Fanaroff AA, eds. Fanaroff and Martin's Neonatal-Perinatal Medicine. 12th ed. Philadelphia, PA: Elsevier; 2025:chap 89.
Greenberg JM, Narendran V, Brady JM, Nathan AT, Haberman BB. Neonatal morbidities of prenatal and perinatal origin. In: Lockwood CJ, Copel JA, Dugoff L, et al, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2023:chap 73.
Maqbool A, Liacouras CA. Normal development, structure, and function of the stomach and intestines. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 374.
Review Date: 4/6/2025
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.