Ah, enemas! Everyone's favorite topic! (No? Just me?) You've probably heard that porn stars use them to prep their bodies for anal, as do some civilians. You also probably know that enemas are a part of BDSM play and slave training. For the most part, they seem pretty harmless - it's just water flushing out your bum, right?
Well, sort of. The information available to us about enemas used in a sexual context is pretty mixed - so much so that I decided to research the topic from a medical angle by checking out the research and writings of doctors, much like I did with kegels. Enemas of course aren't administered by doctors for sex (unless you're fucking a doctor, I guess), so I took a look at what doctors say about enemas for their clinical purpose, which is to alleviate severe constipation.
Ok, gross, I know - but follow me on this one for a second. In the medical world, enemas are made to clear out your arse and are prescribed as a last ditch effort to get people's bowels moving. The part about that to take note of is that actual doctors will only have their patients try enemas if nothing else works. But why?! Why wouldn't they use handy enemas more frequently, before making people chew their food into liquid, take gallons of fiber pills, and all sorts of other strange treatments? Why aren't these babies used more frequently to administer drugs and supplements to one of the most permeable parts of our bodies - the rectum?
Because of the way your bowels work, which is an important thing for anyone to know before they opt into or out of enemas. When you go number two, your nervous system tells your body to contract to push out poo, but only when a stool has created pressure and stretching inside that area of your body. That's how you know you gotta go! Enemas help patients because they loosen up problematic or slow-moving stuff in there and help flush it out - which, what do you know, is why people will do one before having anal.
The major problem that arises when giving a patient enemas is what will happen over time. The fluid stretches out your intestinal walls more than food does, and your body develops a sort of tolerance for normal stool pressure. It's called laxative intolerance: when performed frequently, enemas can make it impossible to go on your own. Yikes!
Too much enema fluid also depletes your electrolytes. Remember, your rectum isn't just a tube - it absorbs substances into your bloodstream far faster than oral ingestion/digestion can, which is why "butt chugging" can give you alcohol poisoning before you can say "hold my beer." Enemas with tap water, alcohol, any irritants, and a laundry list of other substances are generally warned against. Last but not least, an enema may wipe away trace bits of fecal matter, but it also washes away your mucosal lining, something you need it to keep everything moving in there the way it should and help you avoid rectal tears.
So ok, medical evidence would suggest that enemas are not great - at least, they're not great regularly, and they require precision and training. That's not to say they're totally horrible, evil things or that you should never take one; like I mentioned before, some performers use them to ensure flawless scenes, while many people incorporate them into BDSM play, and both groups generally know the risks associated with enemas as well as how often their bodies can handle them.
For the average person just trying to be squeaky clean for anal, though? The risks (dependence, anal irritation, permanent damage, diminishing the good bacteria flora in your intestines) outweigh the benefits.
If you've had a poo within the last three to four hours, chew your food slowly and thoroughly, eat a balanced diet with plenty of plant life, and aren't so drunk that you can't remember if you've done any of that, there is probably an undetectable amount of fecal matter in your rectum, and you don't need to fuss with an enema to have poo-free anal. Your best asset is simply a knowledge of your body's digestive system - and how you can use it to your anal advantage.