Infectious diarrhea and hygiene

A friend mentioned how sick she had just been with diarrhea. She said her preschooler had it, then she got it, then her husband, then her father.

Should I be reluctant to eat the other half of her sandwich? (that is, aren’t infectious diarrheas spread via fecal matter?)

From here:

Seeing as the most likely method of transfer in this case is probably through the preparation of food (with dirty hands), I’d skip the sandwich.

God, this is the kind of thing you don’t mention at work. And then follow it up by offering a sammich? Classy.

The only thing worse than offering your sandwich while discussing the contagious diarrhea ravaging your house is offering the sandwich and not discussing it.

Somebody at work once mentioned a shit sandwich we’d all take a bite of, I don’t think that’s what they had in mind.

Bleeech, you’re actually considering the sandwich?

Not for a second, but I was curious if I was being weird.