According to the ancient legend, Soiletheus stole the first slug of excrement from Xanus (chief Jaoist diety). Xanus found himself irate and chose to punish all men by cursing each of them with an anus so that they would never forget.
Scholars have suggested that the Grecian tale of Prometheus is cognate, or possibly may have even had its origins here.
"The heathen Jaoist priest gripped the wooden idol of Soiletheus. Then, without shame, demonstrated to onlookers how capacious his toga truly was," (Journal of a Crusader)