I agree that it would be best for her to go out on a couple of dates and make sure that she is really interested in the guy before telling him her story. And that's how I would approach it, by telling him the whole story.
Everyone who hears how sick I was before surgery is very compassionate and understanding when I tell them that I had to have my colon removed to save my life.
Dx'd Crohn's in '99 at 28. Proctocolectomy and ileostomy in '06.
Disease-free, medicine-free, and very thankful to be healthy again :)