Let me add these words of encouragement:
My Dad had a similar experience. But he was not a young man at the time. He was in his upper 60s. Same blockage, same slow diagnosis, same 7 or so inches of intestine removed.
They put him on chemo, which made him a little sick and a somewhat tired. Didn't have many sessions with the IV, and then switched exclusively to an oral medication. That made him sunburn easily, so he wore sunblock when he went down to the softball field to watch the games, which was a big part of his summer, even before he retired. (He'd been an infielder and a great base stealer even as late when I was young. :) ).
He lived for over a dozen more years. Even then the cancer never returned, and it was 20 years ago, things have improved since then. It was Alzheimer's that finally got him.
So, there is not just hope, there is every possibility of a great outcome.
Thanks for sharing that encouraging story about your Dad. It was such a surprise, you hear hoofbeats, you expect horses, not zebras. :(