I have an 18 yr. old daughter with CD. She's in her first year of college this year, and is doing well right now. She was also a competitive figure skater for many years, and is coaching now. This sort of parrallels what you would like to do with dance, so as you can see, these things are certainly attainable.
There will always be a degree of uncertainty with this disease, but there are successful treatment options that will work. The best things you could do is to educate yourself as best as you can about this disease, and make sure that you have a GI that you feel confident in.
Also, there are many good people on this forum that can and look forward to helping you. Please continue to ask questions here, and look for support. As indicated earlier, some of the situations your read about here can sound scary, but they are usually severe cases, or the very new that haven't tried treatment options yet.
I can't comment on the residence washrooms, as my daughter is commuting from home this year.
Good luck with everything. I'm sure you'll have a bright future ahead of you.