What does the sentence "Oppsie,i had a poopsie." meaning?
Like this section, at 1:11 the girl said "Oppsie,i had a poopsie."
Does the word "poopsie" means "fart" ?
Site: https://www.youtube.com/watch?v=aAlojdvtO9c

Thank you.

Question

What does the sentence "Oppsie,i had a poopsie."  meaning?
Like this section, at 1:11 the girl said "Oppsie,i had a poopsie." 
Does the word "poopsie" means "fart" ? 
Site: https://www.youtube.com/watch?v=aAlojdvtO9c

Thank you.

Answer

It is just a childish way of saying that they have soiled themselves, i.e. pooed their pants.