The circumstance that arises when a baby's poop is so explosive that it transcends the bonds of the diaper. May be exacerbated by the flailing tyke's tendency to "spread the news" with involuntary arm and leg motion. Usually demands the attention of multiple adults.
Some shituations can only be properly addressed with a garden hose.
An exersaucer is one of those circular things that a baby sits in and is surrounded on all sides with entertaining toys. They used to be called a walker until the lawyers made the manufacturers remove the wheels.
Anyway, an EXCRESAUCER is what they become when the little tyke takes a shituation in the exersaucer. This happens frequently enough to deserve a new word.
Little Buford took a shituation in his excresaucer and now we have to incinerate the damn thang