The Flux is a common term for any illness that causes the sufferer to void large amounts of matter from their person in a short time. Privy doors flap when the Flux comes to town.
The Bloody Flux is a particularly unpleasant strain, often believed to be a punishment from the gods to the impious. The cures for it are certainly foul, including the inhalation of sulphurous fumes, feeding up with blood sausage, "stopping" with cork and wax or greasing with linnet and pork fat. It has an average duration of three days before the illness runs it course.[1a]