You can live without intestines, but not without nutrition. There are different ways of getting nutrition into people when the bowels don't work.
Usually, with bowel dysfunction, all they need is a good rest. People are often put on bowel rest and get nutrition through an IV (it's the big white bag, if he's on it). It's not ideal, but it works.
If there is a specific reason that that his bowels have stopped, it needs to be addressed, obviously, and I'm sure his docs are working on that. If there is one segment that's a problem, or an obstruction, it may require surgery.
Best of luck with that, I'm sure it's hard on the whole family.
they can replace them but there's a very slim chance it will work. And if they dont start working again then he will die.