Not at all a study, just an anecdote, but as an enema taker without a gallbladder I’m fairly sure that taking an enema temporarily increases my liver’s flow of bile. I can see the color in what I expel and feel a ridiculously increased urgency to expel if I take an enema when I’m struggling with too much bile in the first place.
While I’ve sadly needed to give up all but the occasional sip of coffee, I used to drink French press made with a metal mesh filter that allowed all of the oils/flavenoid compounds through. I did this even as my gallbladder started to be very poor at is job, and when I’d drink French press coffee, bile and whatever was in its path would quickly run straight through me. I did conduct the experiment using a paper filter, which seemed to remove most of the volatile/fat soluble compounds that produced the effect.
In sum, I suspect that a coffee enema using coffee that still had its bioactive oils would temporarily increase one’s bile flow.
Does this amount to a detox? Well, it can make you poop. And bile does carry some toxins out of the body as you do so. So maybe it does make that happen a tiny bit faster than otherwise. I wouldn’t count on it to undo a lifetime of rough living. I also suspect that most enema coffee is handled in a way that decreases or removes the compounds that cause this bile dump, but I’m willing to believe that taking it via the rectal route could, in theory, bring more of what’s left to the liver.
Can enemas make you feel great due to increasing your serotonin and emptying an uncomfortable bowel? Yes. Can caffeine, via either end, make you feel focused and as if your life is more worth living? Also yes.
(Sigh, RIP the taste of good French press and the time when I could have caffeine without adverse effects.)
So…I totally believe coffee enemas could make you feel good, and I suppose have some marginally detoxifying effect, but I struggle to think it’d be enough to get ahead of any real problems or abuses of your liver.