Mine went the other way -- I started with the permanent ileo because they were pretty sure I had Crohn's, and then the test came back that is was more likely UC (but still could be Crohn's). I am older, which makes a difference, but I feel fine with how things worked out. I just wanted to be done with surgery and sickness; I didn't want to have to worry about urgency w/the j pouch, and I was OK with having the bag. If it really is UC, that's a bonus, then I'm done for sure.
I am not sure what I would have done if I were younger, though.
One thing to keep in mind with being young, is that the research will get better, and some of the surgeries might change too. My doctor said that he thinks Crohn's is really about ten different diseases, and UC fewer..... wouldn't be surprised when they sort out some of the genetic things if there will be much better answers before surgery as to who is likely to have problems and who not. Crohn's and UC are clearly kind of fuzzy categories at their boundaries.
So, I wouldn't be positive that not having the surgery right away means having a bag for the rest of your life, that's all I'm saying..... although I can also see where if you're going to do it, you might not want to wait ....
It is hard decision, and as Stephanie says, yours alone.
48 years old, female.
2004 dx indeterminate colitis. Back and forth between Crohn's and UC dx. Many drugs, minimal success.
2010-11 Crazy skin and eye complications, high fevers, bad flaring. Out of good drug options, tired of scary drugs.
Feb 2011 -- proctocolectomy with permanent ileolostomy; abscess, blood clot. Still healing, still glad for the surgery