I think people are actually a lot more supportive of it than you would think.
I got IBS in High School and I've been in three serious relationships since then. All three were very supportive of me, and it never interfered.
For example, my college boyfriend actually SPRINTED home a mile from a restaurant we walked to back to our dorm because I thought I was about to have a major attack within seconds. haha at one point he even carried me along the way.
The others have completely understood when I've gritted through my teething saying "NEED BATHROOM NOW!"
There's definitly hope.. and it sounds like many of us haven't had too many problems. good luck.