General pathology · Paediatric pathology
Necrotizing enterocolitis: why the premature gut is vulnerable !
- Mechanism
In the preterm baby, an immature gut, newly arrived bacteria and feeding combine into an inflammation that can kill the bowel wall.
Updated 2026-11-01
What it is
Necrotising enterocolitis is the commonest acquired gastrointestinal emergency of the newborn and affects mainly preterm infants after enteral feeding starts. Its cause is multifactorial: an immature mucosal barrier, an exaggerated immune response to the flora and unstable blood flow. Breast milk is the main protective factor.
Structure
- Gross: distended, friable, congested or gangrenous loops; sometimes perforated.
- Microscopy: mucosal oedema and haemorrhage, coagulative necrosis that may be transmural, inflammation and gas bubbles in the submucosa.
- In the repair phase, granulation tissue and fibrosis appear and may narrow the lumen.
Step by step
- The preterm gut has loose tight junctions, little mucus and slow motility.
- Enteral feeding begins and a poorly diverse bacterial flora colonises the lumen.
- Bacteria activate epithelial receptors (such as TLR4), which are highly expressed in the immature gut.
- Cytokines and platelet-activating factor are released: inflammation, epithelial injury and vasoconstriction.
- Bacteria and their products cross the barrier; ischaemia and infection kill the mucosa and then the whole wall.
- The necrotic wall may perforate, causing peritonitis and sepsis.
Clinical notes
- Feeding intolerance, abdominal distension, bilious gastric residuals and blood in the stools.
- Systemic signs: apnoea, temperature instability, lethargy and, in severe cases, shock.
- Advanced or perforated forms need surgery.
Test yourself
Think of the answer, then tap the question to see it.
What is the characteristic X-ray sign of necrotising enterocolitis?
Pneumatosis intestinalis: gas inside the bowel wall.
Which segment of bowel is most often affected?
The terminal ileum and the proximal colon (caecum and ascending colon).
Which feeding factor protects against necrotising enterocolitis?
Breast milk, which supplies IgA, lactoferrin and oligosaccharides that favour a healthy flora.
Which sequel can follow an extensive bowel resection for this disease?
Short bowel syndrome, with malabsorption.
Related
- Prematurity and fetal growth restriction
- Infarction: red vs white, and what decides the damage
- Patterns of necrosis: coagulative, liquefactive, caseous, fat, fibrinoid, gangrenous
- Hypoxia, ischemia and reperfusion injury
Related conditions
- Necrotising enterocolitis
- Prematurity and its complications
- Short bowel syndrome
- Neonatal sepsis
- Small bowel obstruction
Elsewhere in DurgiPedia
- Neonatal immunity: maternal IgG and breast-milk IgA
- Splanchnic and portal circulation
- Small intestine: villi, crypts, enterocytes, Paneth cells; duodenum vs jejunum vs ileum
- Enteroendocrine cells and GALT
- Pattern recognition: PAMPs, DAMPs, Toll-like receptors
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Necrotizing enterocolitis: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Preterm birth (World Health Organization, 2026).
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Representative model, for educational purposes only.