In Dark Carnival, a bile jar comes in really handy at the end of map 4, the Farms, for passing the gates and going upstream the flow of zombies without taking too much damage. Of course, most noobs, if they have a bile jar, tend to waste it before that critical moment -_-' but that's not the issue...
My question is: is at least one bile jar guaranteed to spawn somewhere in Dark Carnival before map 4's crescendo event, in every instance of that campaign?