If your looking at losing a big chunk of your ilium removed, they might give you an iliostomy, not a colostomy.
Please don't take this as condescending as I just learned this yesterday when I was in seeing my GI. He threw the word at me and I about fell over. I'd been so worried about my colon having issues for so long as the thought of a colostomy freaks me out to no end, as it obviously does with you two.
My GI is a fabulous man! He spent ten minutes of my appointment spending time explaining the pill cam to my daughter who didn't know they existed. He brought out a sample and we discussed how it works, what the protocol is and that if it gets stuck in there it's usually just stuck, not like lit corks your intestines like a bottle.
He then mentioned iliostomy and that it will be up to my surgeon and what he thinks when he gets in there. He's actually spending this time between appointments trying to find the best surgeon for me (my old surgeon had an accident when he was on vacation and is a quadriplegic - therefore not able to work on me any longer), who will spend the time working this all out before he goes cutting willy-nilly.
I guess that's the biggest piece of advice I can give - make sure you're completely comfortable with your surgeon, your life is in his/her hands, literally. Do not go under the knife until every one of your fears have been allayed and your questions answered. This is a big scary, but trusting in the person cutting on you is a big step in making it all easier.