You're faced with a difficult choice and you have my empathy. I have a few comments and suggestions. If you want to try *everything* before giving in to surgery, there are still more things to try.
Has your gastro done a colonoscopy and tried to see for himself what the stricture looks like inside? Can he get to it? I'd guess you've already done this, but if not, it's worth doing. He might be able to see for himself how much is scarring vs. how much is inflammation.
Secondly, while 6mp is a good med for lots of people, it doesn't always work for everybody. And it doesn't always reverse damage that's been done (you might say it's better at preventing than reversing damage).
But it's possible a different medication could improve the stricture. Have you been on prednisone before? If so, did the stricture improve while on it? Or, since your stricture is in the terminal ileum, you could try Entocort (since it's most effective there). You could even try Remicade or Humira and see how the stricture reacts to those.
Those are just a couple of suggestions if you really want to put off surgery longer and give meds every chance to work first. I'm not saying surgery is something terrible and to put it off at all costs, just that once you remove a section of bowel, there's no putting it back in; so it's generally recommended to try meds as much as possible before doing surgery.
As I stated before, it's a tough call for you and I feel for you as you struggle with this dilemma. I have a couple more comments and thoughts.
One, as I mentioned before, some people just never get a response to 6MP, no matter how much or how long they take it. Does the fact that you got no improvement mean your stricture is all scar tissue? Probably, but maybe not. Maybe you're just a non-responder to 6MP. So, again, you're back at square one: Is it inflammation or scar tissue?
You said your doctor believes Remicade or Humira are too risky? But he's recommending surgery? Uhm, to be blunt, that's crazy talk.
How can Remicade/Humira be more risky than putting you under anesthesia, cutting you open, and removing however many inches of intestine, then closing it all back up....
I would venture to say a great majority of docs would disagree with your doctor's position on this one. Surgery is almost always considered more risky than these meds.
Having said that, I'm not trying to scare you out of surgery, and I think its risks aren't very high. But they are definitely there (I had a sinus surgery go terribly wrong, a surgery that was supposed to be "routine" endoscopic surgery, so I'm a bit biased here, admittedly.) What did somebody say about surgery? "The only minor surgery is the one done on somebody else. Any surgery done on you is MAJOR surgery!"
I would advise you to reconsider trying those meds. I'm not saying "do it"; I'm just saying consider it more. If it turns out that your stricturing is from scar tissue and these meds make it worse, well, you'll have surgery, which you're heading towards anyway, so no net harm done (yeah, I know, easy for me to say!)
One other possible thing to consider, which would not be fun to try at all, is an extended period of time (weeks? months?) on basically a liquid diet. Some people get a good response from that. But, yeah, that might be really tough to do.