Infant with rectal bleeding and vomiting. could this be necrotizing enterocolitis?

Yes: Necrotizing enterocolitis is a disease that usually only affects prematures. Rectal bleeding and vomiting should be checked out with your physician regardless of the age of the infant as it could be something serious.

Milk protein allergy: Necrotizing enterocolitis occurs in premature babies and only rarely in full term babies (ie born 37 weeks or later). Babies with nec are sickly appearing and should be attended to immediately. If the baby is about 1 month old and you are getting vomiting and blood in the stool you should speak with your doctor about milk protein allergy (mpa). Usually the baby is not sickly appearing with mpa.

Please see answer: Necrotizing enterocolitis is a bowel disease that typically affects preterm infants, infants less than 37 weeks when born. Full term infants may be affected by this condition but it is rare and very unlikely. If the infant is full term, other diagnoses would include malrotation with volvulus. Regardless, it is important to seek prompt medical attention for this condition.