What Is Necrotizing Enterocolitis (NEC)?
Necrotizing enterocolitis (NEC) is a serious and often life-threatening intestinal disease that primarily affects premature infants. The name itself describes what happens: “necrotizing” means the death of tissue, “entero” refers to the intestine, and “colitis” means inflammation.
In NEC, the lining of the intestinal wall becomes inflamed and begins to die. Bacteria invade the damaged tissue, causing infection that can spread rapidly. In severe cases, the intestinal wall develops holes (perforations), allowing bacteria and stool to leak into the abdomen — a life-threatening emergency.
NEC is one of the leading causes of illness and death among premature infants in neonatal intensive care units (NICUs). It affects an estimated 1 in 1,000 live births overall, but the rate is dramatically higher among very premature and very low birth weight infants, where it can affect up to 10% of babies.
What Causes NEC in Premature Babies?
The exact cause of NEC is not fully understood, but research has identified several key risk factors that significantly increase a premature infant’s vulnerability:
Prematurity
The single greatest risk factor. Babies born before 32 weeks of gestation have immature intestinal barriers, underdeveloped immune systems, and reduced blood flow to the gut — all of which make them far more susceptible to NEC.
Cow’s Milk–Based Formula
Multiple studies have shown that premature infants fed cow’s milk–based formula (such as Similac and Enfamil) have significantly higher rates of NEC compared to those fed an exclusive human milk diet. This is the central allegation in NEC lawsuits against formula manufacturers.
Immature Gut Barrier
Premature infants have an underdeveloped intestinal lining that is more permeable to bacteria. This “leaky gut” allows bacteria to invade intestinal tissue more easily, triggering the inflammatory cascade that leads to NEC.
Bacterial Colonization
Abnormal bacterial colonization of the premature infant’s intestine plays a role in NEC development. The NICU environment, antibiotic use, and formula feeding can all alter the gut microbiome in ways that increase NEC risk.
Reduced Intestinal Blood Flow
Conditions that reduce blood flow to the intestines — such as a patent ductus arteriosus (PDA), birth asphyxia, or certain medications — can contribute to intestinal tissue damage and increase susceptibility to NEC.
Signs and Symptoms of NEC
NEC can develop suddenly and progress rapidly. Parents and caregivers should be aware of these warning signs:
Early Warning Signs
- Feeding intolerance (residuals, vomiting)
- Abdominal distension (bloating)
- Bloody or dark stools
- Lethargy and decreased activity
- Temperature instability
Severe / Emergency Signs
- Abdominal wall redness or discoloration
- Absent bowel sounds
- Cardiovascular instability
- Respiratory distress
- Signs of sepsis (shock)
How Is NEC Diagnosed?
NEC is diagnosed through a combination of clinical symptoms, physical examination, laboratory tests, and imaging. The hallmark diagnostic finding is pneumatosis intestinalis — air bubbles within the intestinal wall visible on an abdominal X-ray. This is considered the gold standard for confirming NEC.
Doctors use a system called Bell’s staging criteria to classify the severity of NEC from Stage I (suspected) through Stage III (advanced/complicated). Stage III includes intestinal perforation and requires emergency surgical intervention.
Laboratory findings may include abnormal white blood cell counts, low platelet counts (thrombocytopenia), metabolic acidosis, and elevated inflammatory markers — all of which help confirm the diagnosis and guide treatment decisions.
NEC Treatment
Medical Management
For Stage I and early Stage II NEC:
- All feedings stopped (bowel rest)
- Nasogastric tube for decompression
- IV antibiotics (7–14 days)
- IV nutrition (TPN)
- Serial X-rays and monitoring
Surgical Intervention
For Stage III or failed medical management:
- Exploratory laparotomy
- Removal of dead bowel tissue (resection)
- Ostomy creation (stoma)
- Peritoneal drain placement
- Possible multiple follow-up surgeries
Approximately 20–40% of NEC cases require surgery. The mortality rate for surgical NEC is significantly higher than for medically managed cases, and babies who require extensive bowel resection face lifelong complications.
Long-Term Complications of NEC
Even babies who survive NEC may face serious, lifelong health challenges:
Short Bowel Syndrome
When large sections of intestine are surgically removed, the remaining bowel may be unable to absorb adequate nutrition. This condition can require long-term IV nutrition (TPN) and may necessitate intestinal transplantation.
Feeding Difficulties & Failure to Thrive
Many NEC survivors have ongoing feeding intolerance, food allergies, and difficulty gaining weight. Some require specialized diets or feeding tubes for years after their initial illness.
Neurodevelopmental Delays
Studies have shown that NEC survivors have higher rates of cognitive impairment, motor delays, and cerebral palsy compared to premature infants who did not develop NEC. The prolonged illness and multiple surgeries contribute to these outcomes.
Intestinal Strictures
Scar tissue from NEC can cause narrowing of the intestine (strictures), leading to bowel obstructions that may require additional surgery months or years after the initial episode.
Death
NEC has a mortality rate of 20–30% overall, and up to 50% for infants who require surgery. It is one of the leading causes of death in NICUs.
The Link Between Formula and NEC
The scientific evidence connecting cow’s milk–based formula to NEC in premature infants has been building for decades. Multiple peer-reviewed studies have demonstrated that premature infants fed an exclusive human milk diet have significantly lower rates of NEC compared to those fed formula.
The American Academy of Pediatrics has recommended breast milk as the preferred nutrition for premature infants specifically because of the NEC risk. Despite this evidence, formula manufacturers like Abbott (Similac) and Mead Johnson (Enfamil) continued to market cow’s milk–based products for use in NICUs without adequate warnings about the NEC risk.
This failure to warn is the foundation of the NEC baby formula lawsuits. Juries have already awarded more than $555 million in NEC cases, finding that manufacturers knew about the risk and failed to act.
Your Legal Rights
If your premature baby developed NEC in the NICU, you may have a legal claim against the formula manufacturer, the hospital, or both. Families across the country are pursuing justice, and courts are holding manufacturers accountable.
You don’t need to know exactly what caused your baby’s NEC to find out if you have a case. Our legal team works with medical experts to investigate every potential cause and identify all responsible parties. The case review is free and confidential.
Frequently Asked Questions
What is NEC in babies?
NEC (necrotizing enterocolitis) is a serious intestinal disease that primarily affects premature infants. The intestinal wall becomes inflamed, tissue dies, and bacteria can cause life-threatening infection. It is one of the leading causes of death in NICUs.
What causes NEC in premature babies?
The leading risk factors include prematurity, cow’s milk–based formula feeding, an immature intestinal barrier, abnormal bacterial colonization, and reduced blood flow to the intestines. Premature infants fed formula have significantly higher NEC rates.
Can NEC be prevented?
Research shows NEC risk can be significantly reduced with an exclusive human milk diet, proper NICU feeding protocols, slow feeding advancement, and early detection of warning signs. Despite this evidence, many NICUs continued using cow’s milk–based formula.
What are the long-term effects of NEC?
NEC survivors may face short bowel syndrome, TPN dependence, feeding difficulties, developmental delays, intestinal strictures, and increased risk of neurodevelopmental impairment. Some require lifelong medical care and multiple surgeries.
Can I sue for my baby’s NEC?
Yes. If your premature baby developed NEC in the NICU, you may have a legal claim against the formula manufacturer, the hospital, or both. Juries have awarded over $555 million in NEC cases. Contact us for a free, confidential case review.
Get the Answers You Deserve
If your premature baby developed NEC in the NICU, our team can help you understand your legal options — at no cost.