Necrotising Enterocolitis

Necrotising enterocolitis (NEC) is a disorder affecting premature neonates, where part of the bowel becomes necrotic.  It is a life threatening emergency. Death of the bowel tissue can lead to bowel perforation. Bowel perforation leads to peritonitis and shock.

The cause of necrotising enterocolitis is unclear. There are certain risk factors for developing NEC:

  • Very low birth weight or very premature
  • Formula feeds (it is less common in babies fed by breast milk feeds)
  • Respiratory distress and assisted ventilation
  • Sepsis
  • Patient ductus arteriosus and other congenital heart disease



  • Intolerance to feeds
  • Vomiting, particularly with green bile
  • Generally unwell
  • Distended, tender abdomen
  • Absent bowel sounds
  • Blood in stools

When perforation occurs there will be peritonitis and shock and the neonate will be severely unwell.



Blood tests:

  • Full blood count for thrombocytopenia and neutropenia
  • CRP for inflammation
  • Capillary blood gas will show a metabolic acidosis
  • Blood culture for sepsis

Abdominal xray is the investigation of choice for diagnosis. This is done front on in the supine position (lying face up). Additional views can be helpful, such as lateral (from the side with the patient on their back) and lateral decubitus (from the side with the neonate on their side).

Xrays can show:

  • Dilated loops of bowel
  • Bowel wall oedema (thickened bowel walls)
  • Pneumatosis intestinalis is gas in the bowel wall and is a sign of NEC
  • Pneumoperitoneum is free gas in the peritoneal cavity and indicates perforation
  • Gas in the portal veins



Neonates with suspected NEC need to be nil by mouth with IV fluids, total parenteral nutrition (TPN) and antibiotics to stabilise them. A nasogastric tube can be inserted to drain fluid and gas from the stomach and intestines.

NEC is a surgical emergency and requires immediate referral to the neonatal surgical team. Some neonates will recover with medical treatment. In others, surgery may be required to remove the dead bowel tissue. Babies may be left with a temporary stoma if significant bowel is removed.



  • Perforation and peritonitis
  • Sepsis
  • Death
  • Strictures
  • Abscess formation
  • Recurrence
  • Long term stoma
  • Short bowel syndrome after surgery


Last updated January 2020