Stage 1. During, and especially after, a run when you feel like you're going to drop the biggest heat stick down your leg if you can't reach the pot in time. Stage 2. Any hold up getting to a dump station and you're sure you're going to blast sloppy bum slosh everywhere. Occurs within minutes.
Be wary of Runner's trots misdiagnosis. A full blown trotsies sesh will leave you wishing you had a super-soaker 7,000,000 to powerwash your asshole.
JP came flying in the house after his run, smashed through the bathroom door and took to destroying the can for 26 minutes. Damn trotsies.