@SZapper - I agree with you about eating. When I was younger, if I had the stomach flu my mom would insist on something called the BRAT diet for a day or so after. I believe the acronym stands for bananas, rice, apple sauce and toast. I guess all that stuff isn't too hard on your stomach.
Anyway, I also wanted to point out that listeria is a serious illness. In fact, I'm pretty sure the mortality rate is around 25%. I would suggest anyone who has listeria (or thinks they have listeria) go to their doctor before they consider treating themselves at home.