Good post. Much sympathy. I never had C. or IBS but when I was racing bikes we used to regularly “go” in the saddle. People who were never athletes (or soldiers) cannot understand.
Or pilots/astronauts, but they wear stuff for that.
I’ve had to slow down to a walk at times on long runs because my pooping impulse would get stimulated. Fortunately, I’ve never had to drop one in my shorts or go behind a bush.
As for that dude in the picture in #6: THAT’s determination (unless that’s from a slapstick movie). Hope there were showers at the finish line.