CBC
Chem
Sepsis evaluation
Coags
Stool +/- heme positive
Pneumatosis on XR is hallmark
Get KUB in supine position and left lat decubitus
Ultrasound
Pseudo-kidney sign - bowel wall with hyperechoic center and hypoechoic rim
Assess for gas bubbles in liver and portal veins
Get KUB in supine position and left lat decubitus
Pseudo-kidney sign - bowel wall with hyperechoic center and hypoechoic rim
Assess for gas bubbles in liver and portal veins
Necrotizing enterocolitis
Emergent
Neutropenic enterocolitis 
Necrotizing Enterocolitis
Food protein-induced enterocolitis syndrome
Volvulus
Intussusception
Testicular torsion