Stage

Systemic signs

Abdominal signs

Radiographic signs

Treatment

IA
Suspected

Temperature instability, apnea, bradycardia, lethargy

Gastric retention, abdominal distention, emesis, heme-positive stool

Normal or intestinal dilation, mild ileus

NPO, antibiotics x 3 days

IB
Suspected

Same as above

Grossly bloody stool

Same as above

Same as IA

IIA
Definite, mildly ill

Same as above

Same as above, plus absent bowel sounds with or without abdominal tenderness

Intestinal dilation, ileus, pneumatosis intestinalis

NPO, antibiotics x 7 to 10 days

IIB
Definite, moderately ill

Same as above, plus mild metabolic acidosis and thrombocytopenia

Same as above, plus absent bowel sounds, definite tenderness, with or without abdominal cellulitis or right lower quadrant mass

Same as IIA, plus ascites

NPO, antibiotics x 14 days

IIIA
Advanced, severely ill, intact bowel

Same as IIB, plus hypotension, bradycardia, severe apnea, combined respiratory and metabolic acidosis, DIC, and neutropenia

Same as above, plus signs of peritonitis, marked tenderness, and abdominal distention

Same as IIA, plus ascites

NPO, antibiotics x 14 days, fluid resuscitation, inotropic support, ventilator therapy, paracentesis

IIIB
Advanced, severely ill, perforated bowel

Same as IIIA

Same as IIIA

Same as above, plus pneumoperitoneum

Same as IIA, plus surgery