I've only ever had one real accident (sorta) as an adult.
I was just finishing up my night gym workout (24/7) and heading back home. Before I set off, I had some whey protein. Way home is about 20-30 minute walk. About half way in, my stomach began 'speaking to me' in a rather aggressive tone. With every minute, diarrhea was overpowering my sphincter to a point where I had to stop here and there to cross my legs and not lose control.
I'm sure many of you can relate when you really need a toilet and the closer you are to it, the harder it is to withhold.
Anyway, in the end, I lost my battle in an elevator and some of it came out. I waddled to the door and straight to the bathroom, drenched in sweat and muscles shaking uncontrollably. It could've been a completely different experience if only I had a diaper on.