Like you, I'm an IBS sufferer in the UK and I'd had trouble explaining IBS to people. I was lucky to find a GP and a consultant who are very sympathetic and helpful. I think my GP finds me interesting - he seems to be using me to educate the rest of his practice about IBS, which can only be a good thing!
I've also suffered from a lot of depression, which was all tangled up with my IBS. Remember that IBS and depression seem to be interlinked - IBS makes you depressed and depression makes your IBS worse. But hang in there!
I found with my partner and family that it was helpful to give them a book on IBS to read - why don't you ask your partner to read the first few chapters of Heather's book, 'IBS - The First Year'? And then talk over what they've read about and try to answer any questions they might have. I know from my fiance that having a partner with IBS can be very confusing and scary, so we've got to give them time and understanding (something that I know isn't easy when you're feeling ill). He gets cross with me if I don't let him know how I've been feeling so that he can be prepared for a bad attack. Keeping on talking is essential.
There are plenty of people in the UK with IBS. We are not alone! Hope this helps.