Enemas are one of man’s earliest medical inventions. Every major civilization since the ancient Egyptians has used them to administer medicines, clear up constipation, refill the body with fluids, or simply to get fucked up.

Throughout history, the rehydration treatments — which involve squirting fluid into one’s colon through the butt hole — have been called a number of different things.

Benjamin Franklin was reportedly a huge fan of enemas back when they were called clysters.

During the Medieval period, the French liberally employed enemas — known then as glisters — as a self-cleansing technique.

Nowadays, enemas are synonymous with colonics, even though they’re technically not the same thing. (The latter involves repeated injections of fluid into the bowels as opposed to just one insertion.)

On college campuses, the term most used for them is “boofing.”

Enemas aren’t only used for health and medicinal purposes. They’re multivalent devices that have long been intended for a litany of uses.

The Mayans used them during rituals, administering substances such as alcohol, tobacco, and water lily flowers through their rectums to get inebriated. Along with horseback riding and getting spun around on a stool to induce dizziness, enemas were seen as a means of curing depression in the 19th century. Enemas containing tobacco smoke were popular in colonial England and often used as a means of resuscitating drowned people.

Today, you’ll find people who do them because they think they can cure autism or make you look younger.

When Gwyneth Paltrow endorsed them in Goop earlier this year as a way of “supercharge[ing] your detox,” more than a few people tried them simply out of curiosity.

And then there are the klismaphiliacs: people with enema fetishes.

Coined in 1973 by Dr. Joanne Denko, klismaphilia is a term used to describe those who experience sexual arousal from administering and/or experiencing the treatment.

An obscure fetish, it’s often shrouded in secrecy and privacy, and rife with discrepancies and variations. Some people get turned-on by the feeling of having a distended belly full of liquid; others prefer the insertion aspect or the release of it. In men, they can also stimulate the prostate gland.

Although not many klismaphiliacs are public about their condition, there is enough recognition behind it to entice most sex stores to carry instruments for performing them. In fact, it’s now easier than ever to buy the tools needed for an enema.

You can buy a single-use, complete “bottle system” at Walgreen’s for $16.99 or peruse through more than 16 pages of listings for enema-related products on Amazon. From rubber bulbs to metal shower heads to plastic syringes, there are an abundance of options to choose from, sold by sellers with names like Pumpkin Carriage, Dear Lady, and Body-Body.

Klismaphiliacs often discover their fetish for enemas after having one administered by chance.

That’s what happened to a retired 66-year-old man in Mumbai, India who had one for the first time to cure a four-day stint of constipation. The man “experienced such a gush of sexual excitement” unlike any he’d had before in his life.

It wasn’t long before he was begging his wife to administer them at all hours of the day — sometimes even in the middle of the night. He preferred having them while lying naked on the bed, and often ejaculated from “the immense joy” of the treatments.

Enemas are also frequently used as precursors to intercourse or substitutes for other sexual acts, like fingering or blow jobs.

According to Psychology Today which culled a number of case studies on the condition, klismaphiliacs can often be experimental to the point of recklessness. In the last few decades, records show that people have tried inserting everything from yogurt, air, whiskey, wine, beer, cocaine, and epoxy resin through the anus.

Sometimes, experienced klismaphiliacs will even top off their rectal concoctions with a ping-pong ball to help keep the fluid in and increase stimulation.

In his research on sexual behavior, Dr. Alfred Kinsey discovered that a fraction of the women in his studies enjoyed having enemas while masturbating.

Others use them to help their bodies climax during sex.

A self-described “married, 54-year-old, postmenopausal woman” started turning to them when she noticed her libido diminishing as she aged.

“I have taken up an activity I did in my 20s when I was single: giving myself enemas,” she wrote to self-help columnist Dan Savage in 2013. “The enema-induced orgasms are fantastic. … I’ll sometimes do it four times in one week.”

Klismaphilia is also easily addictive.

A Florida couple who made headlines in 2013 for their fondness of self-administering coffee enemas, claimed to have each performed 100 a month, or 6,000 in all since they became hooked two years earlier. While Mike averaged about four coffee enemas a day, his partner Trina admitted to using them up to 10 times in a 24-hour period.

“I love the way it makes me feel,” she told ABC News. “It gives me a sense of euphoria.”

There are obvious downsides to having an enema fetish, including the possibility of dehydration, infection, and injury. But the biggest risks are the substances people choose to inject inside their bodies.

One of the most well-known klismaphiliac case involved a man who allowed his boyfriend to pour a batch of concrete into his rectum while they were “fooling around.” It later solidified in his lower bowel and had to be surgically removed.

Doctors Peter Stephens and Mark Taff shared the man’s tale in the American Journal of American Pathology, ending their report with both a warning and prediction.

“As the exploration of anal eroticism increases in popularity, more and more cases of complications as a direct result of their abuse are likely to be encountered,” they wrote.

There is no cure for klismaphilia other than stopping the practice of performing or experiencing enemas altogether.

And most patients tend to not want to do that. Love for rehydration therapies is strong amongst those who have tried it. So strong, in fact, that there is even a monument dedicated to enemas.

Located in front of a spa in southern Russia, the brass statue weighs 805 pounds and is 5-feet tall. Molded to resemble a traditional bulb-shaped enema, it’s held aloft by three naked cherubs with smiling faces and delicate wings.

According to the local artist who made it, the sculpture is meant to invoke the style and feel of a Botticelli.

Some might even call it a masterpiece.