I have a shit-related story although not quite as messy..
It was a Friday morning I believe, after going hard on the Thursday festivities, I awoke at around 5:30am still a bit smashed and really needing to take a dump.
Without thinking, I leapt out of my tent and stumbled towards the nearest portaloo. (And yes, portaloo as apposed to long drop. It was in either Kidney Mead or Cockmill Meadow if I remember right ??). Everything was going fine & I finished up my business before I came to the unfortunate realisation that I was too drunk to remember to bring toilet paper, and the walk had sobered me up too much to not care about that.
I remembered that since I had fallen asleep & woken up in the same clothes, my phone was in my pocket so I went to contact someone for bog roll. Alas, no battery. As it was early morning I could already hear a small queue building outside and so in a panic I scanned through the inside of the portaloo for anything to help the situation. And then there it was.
A discarded Walkers crisp packet. Salt & Vinegar. You can only imagine how that went down.
Moral of the story: REMEMBER TO BRING TOILET PAPER!