You've just had a shower when you notice...
Nice long shower. Hot water just ran out but you're done when you notice...
The sponge/loofa/cloth you've been using has something in it. Closer inspection reveals it's a hard(ish) nugget of poop. Your butt was one of the first things you washed, which means this bit has been lodged in there the whole time you were washing the rest of yourself. Including your face, probably rubbed it through your hair, your genitals etc.
What do you do? Re-shower? Ignore it because...soap? Start crying?
Aaaaand....GO!