what is a dead bowel in a kitten?

  my 6 months old kitten started throwing up on monday was fine tuesday and wed then was sick this morning i took him to the vet and got told after surgery that his bowel was dead and there was a hole in his stomach and that it would be best to put him down, but they didn't really explain what caused this or what it was i am puzzled by it so if you can help please do
Call the vet and have it explained again. We can't help you as we didn't diagnose it.