Not a fan of the crapping your pants in say a marathon or any long distance event. I will say though if you have to dump, chance are you have a bigger issue going on.
I have run marathon's, but they are at the end of an Ironman, I've never run one on it's own as yet. In Ironman races, people often pee on the bike in their bike shorts. I am like um no thanks. I raced bikes for a lot of years and I learned to piss on the bike when the peloton would sometimes do, but never into my bike shorts. The chafing etc would be terrible.
Now stomach troubles in a marathon or other distance event can come on really quickly with some of these gels and drinks if you're not used to them, or just because you're on a bike for five or six hours.
During the 2017 tour of Italy, Tom Dumoulin had to ummm, take a fast natural break, the coverage moved on quickly once they understood what was going on.
https://www.youtube.com/watch?v=Br2fsbH9sy8
At least with long distance swimming you can pee at anytime. I did a 5km race before covid and it was great.
If you have to poop during a sporting event, it is rarely a solid effort. Just saying.