Some constipated older men die from straining on the toilet to pass a stool. Elvis was one of the most famous. Also drug users are sometimes constipated and therfore prone to this misadventure.
Really, though, these photos were great fun to investigate for clues. Mxboots888, I don't think those are female panties we see. They look more like the tops of support stockings. To Steveo1955: hell yes, I agree there sure is blood, and quite a bit of it! It's running clear down the sides of the toilet. That might be the result of a severe nose bleed, but, as you say, "...could be anything."
Thank you, Meatpie, for sharing this unusual pair of images.