When one feels the sudden urge to shit due to the fear of not being able to shit. When one is confined to a small area or being trapped in an area where there is no toilet and as a result gets nervous/has an anxiety attack and has the sudden urge to shit.

Can happen in cars, buses, trams and trains...anywhere that one can not use the facilities.
"Are you ok man?"

"Nah mate, my panic shitting is flaring up again"

OR

That guy has a classic case of the panic shits
by cricketfanbb3/6 December 27, 2011
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An urgent, often hurried restroom visit that results from "holding it" for too long.
Scott had to sprint to the bathroom to drop some huge panic shits after holding it for the whole movie!
by Ahab, Destroyer of Nations February 15, 2014
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