Y'know what? I'll go non-anonymous.
About ten years ago I was forced to go 'roughing it' camping in a state park nearby. It's basically a shit ton of Florida spruce pine and cabbage palms with mosquitos and snakes and raccoons. I hated it. We were only out there for two days, so I figured I could make it without needing to shit in the woods. Toward the middle of the second day it was really hot and I really, really had to shit. We were near a small area where the overflow parking was for people with RVs. I went up to the first one I saw there and knocked on the door, looking around but no one was to be found. I ended up trying the door and when it was unlocked I just went inside. It must have been an easy 110 degrees in the camper, and I was already sweating bad so it only got worse.
I dropped trou, parked it in their narrow stall of a shitter, and proceeded to blast out what can only be described as a torrent of shit-slurry. It wasn't liquid like diarrhea, just loose and sputtery. It went on for a solid minute before it let up, and I was literally shaking. The sweat on my body had turned ice cold and my face was on fire, and I could barely wipe my ass. Finally I stood up, leaving their tiny bathroom coated in my sweat, and flushed.
I don't know if they simply hadn't been there long enough to get any gray water for the toilet accumulated or if they didn't bother filling it because they didn't use their camper crapper, but only a sputter of water came out and made the toilet paper wet on top of my massive dook. It just made the paper form-fit over a small portion of my abomination like someone had made brown mashed potatoes and dropped a pad of butter on top.
Not knowing what to do, I just buckled my shorts up and bolted. As soon as I got outside, I spotted a public use bathroom about a hundred feet down the trail that I'd missed when I came upon the RV.
I made the 10 or 15 minute walk back to my friends and have never told a soul about this until now.
TL;DR: I broke into someone's unattended RV at a campsite to take a huge, horrible shit and then the toilet couldn't flush so I just ran away.