bumsplosion
The blast of diarrhea that occurs when one has been traveling in developing countries. The detonation is usually preceded by a series of tremors indicating the bumsplosion is imminent and it is time to run toward the closest safe blast zone. The bumsplosion can happen anywhere, however, and unless one has made it to a safe blast zone, they usually find themselves laying on their sides at the site of the bumsplosion for the aftershocks.
I tripped on a little girl while running down the beach, feeling the tremors, and I found myself on my side at the epicenter of the bumsplosion, my head on a sandcastle.