There are several good writers of fetish themes. I do so myself from time to time. I do try to keep my stories within the realm of "possible." There are at least two writers out there, who truly STRETCH the imagination.
One good gent, often writes endless paragrpahs, that come from just "chance meetings." In an elevator, as a door to door salesman, and a deliveryman, amongst others. Somehow, some way, the persons he ALWAYS finds a lady, most interested and willing to do enema play. In R/L, the odds of such happenings are likely astronomical. There may indeed, be more people into such themes out there, who are not open about these wants, however, this fellow really bends towards the impossible. He is technically speaking, a thorough writer.
I am the same way with movies, and TV shows. An automobile transforming itself into some human eating machine goes way too far. Not only must the theme fit today, It needs to be "possible" in the future as well. I love Star Wars, and Star Trek. Someday man will indeed make such trips. Walt