Table 1.

Bell’s staging criteria for necrotizing enterocolitis

Stage	Systemic signs	Intestinal signs	Radiological signs
IA (Suspected)	Temperature instability, apnea, bradycardia, lethargy	Poor feeding, emesis, ↑ pre-gavage residuals, mild abdominal distension	Normal or intestinal dilation, mild ileus
IB (Suspected)	Same as above	Above and blood from rectum	Same as above
IIA (Proven)	Same as above	Above + absent bowel sounds + mild abdominal tenderness	Intestinal dilation, ileus, pneumatosis intestinalis
IIB (Proven)	Above + metabolic acidosis + thrombocytopenia	Above + definite abdominal tenderness	Above + portal vein gas + possible ascites
IIIA (Advanced)	Above + hypotension, respiratory acidosis, neutropenia	Above + peritonitis, marked distension of abdomen	Above + definite ascites
IIIB (Advanced)	Same as above	Same as above	Above + pneumoperitoneum