The explosive, and sometimes satisfying, diarrhea one experiences after completing some form of running event, excluding short sprints. Side effects may include burning, itching, or destroyed anus, and/or required decommission of toilet and bathroom for an extended period of time
"Hey, great job on that 5K, want to go hang out with the team?"
"No man, I got a bad case of Runners runs, I'll catch up with you in a bit."
"Are you done in there?"
"Yeah, but you might want some Febreze or matches, I had a bad case of Runners runs."
"What the hell man..."
"Sorry"