Boston buttplug
A desperate last ditch method to stop a bowel movement by inserting one's finger into the anus, in an attempt to block the process.
Bill was trying desperately to make it to the bathroom in time, but when he got there, that fucking time vampire, Sally was screwing around in there again, so he had no choice but resort to using the Boston buttplug to keep from soiling himself, then being endlessly heckled by that bitch Sally.