I got diagnosed just over 2 years ago, where I suddenly got rather ill and lost a lot of weight, going to loo 10 times a day and very tired. I was given steroids although I hadn't been diagnosed with anything yet. No one in my family had a history of Crohn's or UC. While waiting for a colonoscopy date, I went to my GP again and they suggested I go to hospital. This was all over a period of maybe 3 weeks?
Still in hospital a week later, after a colonoscopy and getting the results, it turned out I had UC and my colon was close to rupturing, so had emergency surgery to remove it and have an ileostomy and stoma. This was done through open surgery, so I have a lovely long scar from above my belly button to my crotch. I ended up in hospital for 5 weeks due to various issues while in hospital, mostly due to being so ill before I had the surgery. They said I could have a reversal in a years time though and be back to normal.
A few months later, when a wound from my surgery wasn't healing over, it turned out I still had UC in my rectum and the remaining stub of colon, so a year after my first surgery, I had the rectum and remaining colon removed, and anus sewn shut from the outside, making my ileostomy and stoma permanent. It was either that or still have the rectum and colon removed, but have a J-Pouch, so I was used to the stoma and didn't want to try and handle another new way of going to the loo haha! 
It's sometimes annoying, life with a bag, but I go on all my rides at theme parks (with a stoma guard), have the same job still, getting married next year, and life is pretty good!
I agree with you LetsSplashMummy, some say the worst outcome is surgery but I don't feel ill at all now, on no medication etc. so for now it seems the best outcome! 
Of course, there's other extraintestinal symptoms that can appear e.g. arthritis, skin problems etc., but I don't seem to have any yet touch wood.