This is a true story:
On a bus trip across the subcontinent the tourists were so afflicted by diarrhoea there was an arrangement made with the bus driver that anyone with a desperate need should run up to the front of the bus and he would immediately stop so they could get out and relieve themselves.
On one such occasion a young lady exited the bus and vaulted over a low limestone wall into a field of lush grass. She took a long time to return, and when she did it was from down the road, and she appeared to be covered from head to toe in brown flowers.
It turned out the "field of grass" she had jumped into was a thin, grass covered crust covering a deep and extensive cesspit servicing the town just up the road. The unfortunate girl found herself completely submerged and had to swim through the excrement to get to a point where she could climb out, and hence her reappearance from down the road.
The poor girl was forced to sit at the very back of the bus with the back window wide open while all the other passengers squeezed into the frontmost seats, as far away from the smell as seating would allow.
To avoid such embarrassing incidents in the future, the locals provided a portaloo service which would run to the tourist buses when they stopped.