flickr user M. Francis McCarthy

"Fear Factor" shot an episode last summer that was so gross that NBC spent months deciding whether or not it should be aired.

The challenge is this:  The teams of two must completely drink full glasses of donkey fluids.   There was one glass of donkey pee, and a glass of donkey semen.

"Sources" tell TMZ that the higher-ups and NBC deliberated on whether or not they should air this stunt, but ultimately, they decided to give it the green light.

Sure, 50k is a lot of money - but they will have to offer up A LOT  more cash than that to get me do this stunt.

The episode will air this coming Monday, Jan. 30th.

If you can stomach it, TMZ has a picture of the glasses of donkey fluids.

SPOILER: And for the record, their source says "multiple" contestants DO finish the task.

Here is a video clip of the latest gross stunt on Fear Factor -
eating grasshoppers, rat hair chips and blood-maggot salsa: