Riley ate a fish burger from a street vendor and at the time was concerned it didn't smell right but decided to eat it anyway.  Later that day he started to feel unwell.
I feel terrible, I have stomach pain. Did you eat something spoiled? I think I did, I ate a fish burger that didn't smell right. That must  be it then, where did you get it. I bought it from a street vendor. No wonder you are sick then.