Welcome and thank you for opening up to us about your situation. If the problem is that she doesn't feel sexy with her new body, maybe some pretty lingerie would help. Make sure you tell her often how beautiful you think she she is, especially when you see her naked. That really helped me accept my new body.
If you have children, do you two ever go out alone? A romantic night out with dinner and movie might help her get in the mood. And don't forget to cuddle with her in bed. Since we can be self-conscious about our stomach areas, spooning is a very good thing. So is KY Warming Jelly.
If she's depressed, maybe she can talk to her gynecologist about it. If it's not depression, but a low sex drive, then there's medication for that, too.
Hope this helps!
Dx'd Crohn's in '99 at 28. Proctocolectomy and ileostomy in '06.
Disease-free, medicine-free, and very thankful to be healthy again :)