I've had IBS for almost 30 years, and yes, it has affected my social life. I am on the quiet, introverted side anyway, but even in high school, I remember declining social events that my friends invited me to. Today,I don't like driving long distances with anyone except my husband/family, and I also decline many outdoor type activities. For a long time, I thought it was just "me." But upon further reflection, lots of that was because I feared getting an attack in public.
I have had to consciously work to overcome this fear. One of my fears was stadiums. But my kids love baseball, and so slowly, I changed my perception of stadiums and now I can attend stadium events without a second thought.
IBS can be very isolating if you let it. I have the personality where I could quite easily hole up at home in front of a computer and think I was fine. But truth is, I need to be around people other than my family. I have to consciously change the way I see myself and this disorder. I have to challenge myself to take risks and be vulnerable. Nine times out of ten, nothing "bad" happens anyway. It is just my fear of "what if..."