First of all, congratulations! You're in for a WONDERFUL ride!!! You must be due in early January...no?
Second...not true that you have to have a c-section, and if that's the only option your hospital is offering, possibly consider another hospital/OB (if you are concerned). (Mine isn't even that large of a hospital and it was never a question.)
I am nearly 10 years out from a colon resection (dx with stage II colon cancer at 23 years old back in February of 1999...and they removed 25 inches of my large intestine) and had my first baby Christmas Eve in 2006. I was really nervous (obviously, but on top of the fact that it was my first baby, I was completely freaked out about adhesions and Lord only knows what else is going on in there now!) and spoke with my OB at length about it. She didn't seem too worried and knew of a few IBD patients who had had resections and then babies, but we decided to bring my oncologist into the loop anyway. (He was a happy camper because it gave him an excuse to have me come into his office once a month to check my surgical scar!)
My biggest concern was that if there were complications during my labor/delivery, I would need a c-section and then we might run into scar tissue or something like that. Unfortunately though, no one seemed to have any solid answers for me, since no one seems to know many women who've had babies after colon cancer. I spoke with a friend of mine who is a surgical oncologist, and he said that the only time he's seen a problem during a c-section is if there was mesh used when a patient was closed up after their original resection. Do you know if you had mesh? If you aren't sure, you can get copies of your surgical reports and read through them, or ask your doc to do it for you. It turned out that I didn't have any, but I had had adhesions after my first surgery, so I was still worried.
Anywho...we (my OB, my onco and I) jointly decided that I should consult a surgeon, which I did. The plan with him was to shoot for a regular delivery and the surgeon (actually, it was a surgical group, which made it a bit easier) was put on call when I went into labor, in case there were any complications and I needed a c-section.
Fast forward a few months and I went into the hospital around 2:30pm...got sent home around 5pm...was back by 7...started pushing around 12:30am and Kyril (pronounced Kiril) arrived at 1:07am 12/24/06. I have three friends that were pregnant and due right around the same time I was...none of them cancer survivors, or colon resects...and I don't even talk about it around them because my labor and delivery was so much easier than any of their! 2 of them had c-sections and both spent longer than expected in the hospital before and after.
I'm not saying everyone who's had a resection is going to have that easy of a time...but I am saying that it's completely possible to have a normal birth after a colon resection. (I will say that the doc and anesthesiologist both thought that I might have been in a little bit more pain because of things stretching inside. I was fully planning on the epidural anyway, so that wasn't a question. You may want to think about that when you're considering whether to go au natural or get the drugs.)
So...that's my long and drawn out version. In a nutshell, definitely talk to your OB about it and have some sort of plan in place, just in case. If you're prepared, Cardinal Rule is that you won't need any of it!
If you want to chat more, feel free to PM me. I'm on baby #2 now. 16 weeks along and feeling like a chunker!