I'm 18 and had my colon remove on 17/3/17 as an emergency procedure due to toxic megacolon. I had a very rare case of UC that came out of nowhere and absolutely smashed me for a solid three or four weeks leading up to my surgery. No symptoms prior, just started feeling fatigued and having to go to the loo far more frequently and passing blood. All symptoms I'm sure you've experienced for far longer than I did. Perhaps it's me dreaming of the good old days of going to the toilet once or twice a day, or the fact that while I respect that the ileostomy saved my life, I don't think I'll ever like having a bag, having to factor changing it and emptying it into my day, and the interrupted sleep every night that makes me say that had the hydrocortisone or the infliximab worked I would have fought UC for as long and as hard as I could. Perhaps it is just the ignorance of my youth. The way is it is this: a total colectomy is an irreversible, life-changing surgery. Unfortunately for me, I didn't have the luxury of considering surgery, meeting my surgery for consultations, meeting the stoma nurses to learn about everything I'd have to do. I have no doubt that your experience with UC is vastly different to mine, but please don't forget the fact that once your colon is gone, that's it.
I can understand how someone who has had UC for a long time would consider surgery due to the idea of it removing the UC completely, and that is absolutely your decision to make, but if I had the opportunity I would have kept my colon for as long as possible.
Don't let me put you off if you are fed up with UC, because as I said, I only had it for less than a month before I went under the knife as an emergency. I also never experienced UC in the way that people have described in so far as going to the toilet 10 to 20 times a day. Fatigue is what destroyed me, but I'm going off track now. Be sure to consider the full extent of this surgery and what having an ostomy entails. For me, I have been alright with the physical change as I am quite good at getting a routine and sticking to it, but psychologically it has been pretty hard at times.
Thanks for reading, good luck with your decision. Whatever it may be.