My workplace allows employees to take sick leave of up to one week without a doctor's note. Essentially if you think that you shouldn't be around other people or know you won't be able to work you can call in letting your project lead and secretary know and that's it.
I was wondering how much information about my ailment should I be expected to provide in such email? I feel like just saying "I need to take a sick day off today." without further explanation sounds just like an excuse not to come to work. On the other hand, say I get food poisoning, do my colleagues really need to know I'm gonna be spending most of my day on a toilet?
EDIT: I should also probably add that I am asking this less as a legal/rules question and more as in ethics / office expectations / conventions question.