I rarely give medical advice, but: I do not recommend this.
People have been talking about coffee enemas since the February 8 episode of My Strange Addiction featured a couple that said they're "addicted" to them:
Humans have been colon cleansing since the dawn of time. Doing so with coffee isn't a new thing either. Back in 1982, Dr. Maurice Shils and Mindy Hermann wrote in the Bulletin of the New York Academy of Medicine about cancer trends:
No one has been able to demonstrate the existence of specific "toxins" as a clinical factor in human cancer. Preoccupation with "detoxification" and "purification" has led to the advocacy of coffee and other enemas to cleanse the bowel of toxins.
So, even 30 years ago toxins were a thing. But it goes back further.
The coffee enema is part of the still-popular Gerson therapy, developed in the 1930s. "How the Gerson Therapy Heals" explains the reasoning behind coffee enemas and how they "stimulate the glutathione-S-transferase system by 700%" and "cleanse the blood." It says the enema route is essential because "patients cannot be expected to consume the therapeutically necessary daily amount of at least one liter of coffee by drinking it." (Although that was written in 1990. A liter is 33 ounces, and now we have Starbucks' 30-ounce trenta.)
The FDA and many physicians and health boards have meanwhile spoken out against all types of colon cleanses. Any time you're filling your colon like that, there's a small chance it will pop like a balloon. Nature even reported a case of procto-colitis with ulcers related specifically coffee enemas. In 1980, the Journal of American Medical Association reported two fatalities in "Deaths Related to Coffee Enemas."
On the other hand, Trina from My Strange Addiction says, "I love the way coffee enemas make me feel."
Infections and explosions aside, that's a huge amount of caffeine. Depending how much is absorbed in the rectum compared to a similar amount via the stomach and small intestine when you drink coffee, Trina is consuming the oral equivalent of 33 cans of Red Bull every day. So yes, "euphoria."
Like we considered in "How Much Caffeine Before I End Up in the E.R.?" humans can potentially tolerate tons of caffeine -- in electroconvulsive therapy, for patients with depression, up to 2,000 mg is sometimes given intravenously -- but many of us go to emergency rooms for much less.
The nice thing about ingesting coffee by the traditional route is that it can still be a calming ritual and a mutual interest with your partner, even when it doesn't involve buckets or hoses, or lying on the bathroom floor four times a day, or "transitioning from floor to toilet seat as quickly as possible."