Coffee enemas have been around since the 19th century (when medical science was a mess) and they persist today (when woo advocates like to hold up the fact that medical practices have persisted since the 19th century as proof that they work). In case you were wondering, they're bad for you.
Potential side-effects from squirting coffee up your asshole include: "electrolyte imbalance, sepsis, colon or rectal perforation, and proctocolitis due to the coffee itself, among others, up to and including death."
Coffee will not "detox" you because detoxing is bullshit.
It wouldn't matter, except quacks tell cancer patients and other people who are sick and need actual medicine, not coffee enemas, to squirt coffee up their assholes.
By the 1920s or so, science had shown that the various symptoms observed in patients with chronic constipation were largely due to distension of the bowel and were not due to autointoxication. As is its wont, scientific medicine moved on from a failed hypothesis. Alternative medicine practitioners, as is their wont, never did, hence the continued popularity of coffee enemas, which are supposed to correct autointoxication both through their physical action removing fecal matter and “stimulating” the liver to produce bile through the absorption of the various substances in the coffee, such as palmitic acids, straight into the portal circulation. Of course, one of those substances, one of the main reasons people drink coffee, is caffeine; so symptoms of caffeine overdose are another set of potential adverse events due to this exceedingly silly alternative treatment. Amazingly, in contrast, Thompson claims that actually drinking coffee instead of doing enemas with it “impairs” liver activity. The evidence for that? The same as for the rest of the article: None.
Starbutts, or: How is it still a thing that people are shooting coffee up their nether regions?