Have a talk someimte with no pressure and tell her that she can really help you just by doing little things. It took my DH a while to realise this, but he's been wonderful. Ask her if she'd read Heather's book...it can help explain alot. And say you really want to try and beat this and you'd love it if she could help you.
Just a few thoughts. My hubby got very good at being my food police...if he saw me going to eat something bad, he'd go "do you really want to be eating that?" and that helped. Also, he got really into discovering new safe foods and finding helpful places we could go out to.
I know it's hard, but it's very important that you don't let the IBS dominate your life. Relaxing and having fun will actually help the IBS as well.