A Poopy Solution
We find a young girl in the sewer, who we learn has been separated from her mother. Quite what her mum was doing down here with her daughter we can't say, and we don't know where she is anyway.
The girl is from the town which is two days' away from the exit, and we can't really take her there without abandoning our mission to find the source of the fish fever hitting the village. We can't really take her to the village either, and not just because of the fish fever, we may not have time to trek all the way to the exit and back again. We suppose we have to take her with us.
We press on. As we head further in to the sewers, we hear some clanking noises ahead, much like the sounds of a sluice gate opening. Sure enough, a wave of poo comes our way. We brace ourselves and shelter the girl as much as possible, and although we are able to withstand the force of the stinky water hitting us, the girl loses her grip and is swept away, presumably towards the sewer exit.
'Well, that problem's sorted itself out.'