In addition to limiting fiber leading up to the race, I heard that avoiding caffeine or acidic coffee in particular for some people works as does avoiding spicy food na fatty foods. Bland food is prefered (like rice cakes) and staying hydrated. And the problem is more prevalent among those newer to running.
If your shorts have pockets, put a few paper towels in them. You won't have to worry about using leaves, especially in the wintertime when leaves can be in short supply.
Congrats on going for a run. I'm guessing many others like me who have been running for years have discovered the "bad" times to run. I used to run early in the morning and nearly every time I ran over~6 miles it was unbearable. I planned my routes to hit porta potties... Now I can run at any time after 9 AM and be fine, though early mornings would still work better for the personal schedule.
Literally one of the most common side effects of running for the common person and it took you 20+ years in a career about running to realize this? It's like this message board is more about crappy politics than running. Oh wait...
If I eat chipotle, i know i need to wait for a dump before running in the morning. That was a lesson learned the hard way. Actually, it was a soft but explosive lesson.
This is hobby jogger sh1t. No pun intended. Any serious runner knows you brew a cup of black coffee prior to your run in order to clear the pipes. I have never had runner's diarrhea using this method.