AKT · Gastroenterology/Acute abdomen & surgical

Necrotising enterocolitis

Ischaemic-inflammatory necrosis of neonatal bowel (prematurity; bacterial invasion of the wall)

Overview

A serious neonatal GI emergency — ischaemic-inflammatory necrosis of the bowel wall, mainly in PREMATURE/low-birth-weight infants (also formula feeding, hypoxia). Presents in the first weeks with feed intolerance, bilious vomiting/aspirates, abdominal distension and bloody stools, progressing to systemic collapse. The AXR signs are key: PNEUMATOSIS INTESTINALIS (intramural gas) and portal venous gas; perforation gives free gas. (Primarily a child-health/neonatal condition — carried here for the radiograph discrimination.)

Recognise

Premature/low-birth-weight neonate (first 2 weeks, on feeds) with feed intolerance, bilious vomiting/aspirates, abdominal distension, bloody stools
Systemic: lethargy, temperature instability, apnoea, shock, DIC; abdominal wall erythema/tenderness
AXR: dilated loops, PNEUMATOSIS INTESTINALIS (intramural bubbly/linear gas — pathognomonic), portal venous gas; perforation → free gas (Rigler, football sign, non-dependent gas on decubitus)

Red flags

PERFORATION (free intraperitoneal gas — pneumoperitoneum) → surgical emergency (laparotomy/drain)
Clinical deterioration/shock; pneumatosis or portal venous gas = established NEC

Differentials & how to tell them apart

Bowel perforation (from NEC)FREE intraperitoneal gas (pneumoperitoneum) — the surgical endpoint; NEC's own sign is intramural PNEUMATOSIS, not free gas (the decubitus film distinguishes them — free gas rises non-dependently)

Spontaneous intestinal perforationisolated perforation in a very preterm infant without the diffuse pneumatosis of NEC

Malrotation/midgut volvulusbilious vomiting + 'whirl'/abnormal contrast — different emergency

Sepsis/ileusdistension without pneumatosis

Necrotising enterocolitis — pneumatosis intestinalis (intramural gas) on neonatal AXR
Jto410 / CC BY-SA 3.0 — Wikimedia Commons

Investigations

AXR (serial — pneumatosis intestinalis, portal venous gas, free gas; the LATERAL DECUBITUS/cross-table film confirms free gas non-dependently); FBC (thrombocytopenia/neutropenia), CRP, blood gas (acidosis), blood cultures.

Management

Bowel rest (stop feeds) + NG + IV antibiotics; surgery for perforation/deterioration

1Stop enteral feeds (bowel rest), NG decompression, IV fluids/parenteral nutrition, broad-spectrum antibiotics, and serial AXRs. Neonatal/surgical involvement.Gate: FREE intraperitoneal gas = PERFORATION → surgery; on an equivocal supine film, a LATERAL DECUBITUS/cross-table lateral confirms free gas by showing it rise to the NON-DEPENDENT side — distinguishing perforation (free gas) from NEC's intramural pneumatosis
2Surgery (resection of necrotic bowel ± stoma, or primary peritoneal drain in the tiny/unstable infant) for perforation or deterioration; long-term: strictures, short-bowel syndrome. (Full neonatal teaching: child health.)

Stop enteral feeds (bowel rest) + NG decompression + IV fluids/TPN — medical management of early NEC

Broad-spectrum IV antibiotics — cover gut flora (e.g. ampicillin + gentamicin + metronidazole)

Surgery (laparotomy / peritoneal drain) — for perforation or deterioration — resect necrotic bowel

Key points

Preterm neonate + feed intolerance + distension + bloody stools + PNEUMATOSIS on AXR = NEC. Free gas means it has PERFORATED — and the decubitus film clinches free gas by its non-dependent pooling (exactly the read that separates NEC from perforation). Bowel rest + antibiotics; surgery for perforation.

Monitor & prognosis

Serial AXR/gas/platelets; surgical threshold.

Significant morbidity/mortality in preterms; strictures/short bowel survivors.

Source: BAPM/RCPCH; cross-ref child_health (neonatal)