Log Wars
When two people press their asses together and proceed to both attempt to shit at the same time. The one whose shit pushes the competitor's shit back into his or her body is the winner.
John and Mark like to play Log Wars. John has several trophies.
Mongolian Log War
When two people press their asses together and create an air tight seal. Then they both shit and try to push the log into the others body.
"Dude, we should have a Mongolian Log War because I bet I can burst a turd out of your chest like an alien."