What could cause bright red blood vomits in a neonate?

Cite this article as:
Yamamoto, L. What could cause bright red blood vomits in a neonate?, Don't Forget the Bubbles, 2014. Available at:
https://dontforgetthebubbles.com/bright-red-blood-neonate/

A 6-day old infant male vomits a large amount of bright red blood at home and is taken to a rural emergency department. The child looks good, but the amount of blood on the baby’s blanket brought in by his mother is very impressive.