Which preposition to use with poo

from Occurrences 1%

This island, and a river on the coast of the continent of Africa, directly east, now called Cameroon River, are said to have taken their names of Fernando Poo from their first discoverer.

through Occurrences 1%

Aw think sometimes it's very weel that four ov eawrs are i' heaven,we'n sich hard tewin' (toiling), to poo through wi' tother, just neaw.

Which preposition to use with  poo