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Necrotizing enterocolitis (NEC) is a serious gastrointestinal emergency in neonates, characterized by ischemic and inflammatory necrosis of the intestinal wall, leading to variable degrees of bowel necrosis, perforation, and sepsis. It predominantly affects premature, low-birth-weight infants.

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https://www.youtube.com/watch?v=EWA7MeqRCFo

Etiopathogenesis

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Mucosal injury → bacterial invasion → coagulative necrosis → intramural gas → perforation / peritonitis.

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Multifactorial pathogenesis:

1. Prematurity – immature intestinal mucosa, poor barrier function, abnormal motility.
2. Enteral feeding – formula feeding increases risk (promotes bacterial overgrowth, higher osmotic load vs breast milk).
3. Intestinal ischemia–reperfusion injury – hypoxia, asphyxia, PDA, sepsis → mesenteric ischemia.
4. Microbial colonization – pathogenic bacteria release endotoxins → inflammation, gas production.

![NEC Risk Factors and Prevention Strategies. NEC risk factors include preterm birth (causing immature intestinal barrier and immune defenses), formula feeding, microbial dysbiosis and local ischemia or hypoxia. NEC prevention strategies include human milk diet, implementation of feeding protocols, transfusion protocols, probiotics and antibiotic stewardship

Colarelli, A.M., MD, Barbian, M.E. et al. Prevention Strategies and Management of Necrotizing Enterocolitis. Curr Treat Options Peds 10, 126–146 (2024). https://doi.org/10.1007/s40746-024-00297-2](attachment:a98569d7-0536-4a8a-9940-063a914c7ac0:image.png)

NEC Risk Factors and Prevention Strategies. NEC risk factors include preterm birth (causing immature intestinal barrier and immune defenses), formula feeding, microbial dysbiosis and local ischemia or hypoxia. NEC prevention strategies include human milk diet, implementation of feeding protocols, transfusion protocols, probiotics and antibiotic stewardship

Colarelli, A.M., MD, Barbian, M.E. et al. Prevention Strategies and Management of Necrotizing Enterocolitis. Curr Treat Options Peds 10, 126–146 (2024). https://doi.org/10.1007/s40746-024-00297-2

Clinical Features

• Typically presents in 2nd–3rd week of life (earlier if very premature).
• GI symptoms: feeding intolerance, bilious vomiting, abdominal distension, bloody stools, abdominal tenderness.
• Systemic symptoms: apnea, lethargy, temperature instability, shock (sepsis).

Modified Bell’s Staging of NEC:

![Panel a shows an infant with a shiny, distended abdomen with periumbilical erythema. In the radiograph shown in panel b, the upper arrow points to portal air, and the lower arrow points to a ring of intramural gas, which is indicative of pneumatosis intestinalis. In Panel c, the arrow points to an area of necrotic bowel in a patient with necrotising enterocolitis.

Photograph courtesy of Dr David Kays, Department of Pediatric Surgery, University of Florida Radiograph courtesy of Dr Jonathan Williams, Department of Pediatric Pathology, University of Florida Photograph courtesy of Dr David Kays, Department of Pediatric Surgery, University of Florida Neu, J. & Walker, W. A. Necrotizing enterocolitis. N. Engl. J. Med. 364, 255–264 (2011) Sitek, A., Seliga-Siwecka, J., Płotka, S. et al. Artificial intelligence in the diagnosis of necrotising enterocolitis in newborns. Pediatr Res 93, 376–381 (2023). https://doi.org/10.1038/s41390-022-02322-2](attachment:edf10b56-846e-4714-a976-7eb7212733e6:image.png)

Panel a shows an infant with a shiny, distended abdomen with periumbilical erythema. In the radiograph shown in panel b, the upper arrow points to portal air, and the lower arrow points to a ring of intramural gas, which is indicative of pneumatosis intestinalis. In Panel c, the arrow points to an area of necrotic bowel in a patient with necrotising enterocolitis.

Photograph courtesy of Dr David Kays, Department of Pediatric Surgery, University of Florida Radiograph courtesy of Dr Jonathan Williams, Department of Pediatric Pathology, University of Florida Photograph courtesy of Dr David Kays, Department of Pediatric Surgery, University of Florida Neu, J. & Walker, W. A. Necrotizing enterocolitis. N. Engl. J. Med. 364, 255–264 (2011) Sitek, A., Seliga-Siwecka, J., Płotka, S. et al. Artificial intelligence in the diagnosis of necrotising enterocolitis in newborns. Pediatr Res 93, 376–381 (2023). https://doi.org/10.1038/s41390-022-02322-2