Behind the Behind: the Anatomy of your Butt

Dr. Evan Goldstein

fundamentals January 30, 2020

Between your cheeks lies an orifice for the taking. And those lucky enough to understand its anatomy are able to truly open up—pun intended. Yet many are still overwhelmed by its supposed complexity, especially when preparing to bottom—both from a cleansing and dilation perspective. Butt I am here to break it down for you. 

A hole is a hole, right? Somewhat. The A-hole is just skin, muscle, a tube/conduit, and a reservoir. That’s it. Not too complex. But, let’s start from the outside, in, make sure we also titillate your prostate, and discuss both how your butt works, as well as how best to work it. 

First and foremost: the infamous buttocks

Who doesn’t love these two cushions? I think they're truly the gateway to your soul. With just a gentle spread, the inner nerve endings culminate on a puckered opening. Due to this sensitivity, rimming is wonderful for foreplay, with its actions allowing the underlying skin and muscle to fully relax. Don’t knock it if you haven’t had it. It’s a wonderful appetizer to anything butt-related and leads one deeper into the anatomy. 

Your skin and underlying muscle stay contracted 99.9% of the day, reflexively relaxing when you need to defecate. You can actually train both to relax during butt play: with proper knowledge of its function, mind-blowing bottoming can be  in your future. 

Getting your skin into shape

 Butt Anatomy


Remember: you can’t go from bottoming nothing to accommodating something huge. It doesn’t work that way. Both the skin and muscle are quite sensitive, getting traumatized easily. Most of us have very thin skin in the anal region, though with proper training, you can toughen the outer core. It’s no different than lifting weights and getting a callus on your palms from the metal bar. Those calluses protect your skin. Using anal dilators over a period of time will accomplish a similar toughening of the skin. Though it takes a good 4 to 6 weeks, it’s totally a worthwhile effort that will prevent trauma in the long term. 

Giving your butt muscles a workout

Now that you get how the skin fares, let’s move on to muscle. There are a total of three circular rings of muscle just inside your hole that needs to learn similar relaxation—the external sphincter, superficial sphincter, and internal sphincter (from out to in). Thankfully, we can accomplish this action simultaneously, while the dilators toughen the skin. Dilation allows for complete skin and muscle relaxation and, more importantly, successful butt play. 

Understanding that these three muscles need to relax sequentially is critical. But you need to be patient to get them to open. I instruct people to use their dilators to truly get to understand this anatomy. Using the 'in-and-out lubed-up action' method until you hit resistance (then stopping) will guide you. It may take 6 to 8 times to fully get beyond the third (or internal) muscle, but please don't get frustrated or defeated. Keep constant pressure, remove, and do it again. This repetitive action is imperative and, over time, you will develop the reflexive relaxation response for full acceptance. 


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On to the inside: meet your rectum

OK, so skin opened: check. Muscle relaxed: check. Now it’s on to your rectum: the tube (or you can use the word ‘conduit') and reservoir (also the name of my favorite bar near the Future Method office that I frequented when I was younger) where the action happens. Beyond the skin and muscles, the rectum is just a cylinder, one where it is imperative that its entire lining is fully lubricated. This allows for that complete glide that will help bottoming be bliss rather than a bummer. Thankfully, with appropriate preparatory dilation, your rectum is well taken care of. Some also use lubricating suppositories and/or a lube shooter to ensure the sleekness is present all the way through. Don’t just assume your top has it under control. 

The colon and the rectum: a big difference

From the tube/conduit (the rectum) to the reservoir (the colon)—a topic of continued discussion. Anatomically, the rectum is only about a foot long and is where the usual impact of penile penetration takes place. Your poop is stored higher up, in what’s called the sigmoid colon. When it’s time to go, poop migrates down into this region. Thankfully, this stimulation causes a pooping reflex, so away it goes, ridding the rectum of any debris [with Future Method taking care of the rest, naturally]. 

With high-fiber supplementation, proper diet and exercise (and regular bowel movements) this reservoir region for the most part is devoid of residual crap. One's penis—no matter how big it is—fits snuggly into this typically ‘Mr. Clean region’ and doesn’t peek around the corner to where poop may be residing. Over-douching stimulates the higher up sigmoid colon, where poop is stored and essentially kicks off the unnecessary reflex of pooping. Large volumes of cleansing liquid and/or excessive amounts of cycles of cleansing may indeed cause more harm than good. 

Finally: the prostate

Butt Anatomy

Last, but not least, the male G-spot, otherwise known as the prostate. This is anatomically on the way internally into the rectum and colon. It’s walnut shaped and about 6-8 cm inside your hole, towards your penis (away from your tailbone). Thankfully, most toys (and Ds) are already angled for a direct hit, so it shouldn’t be hard to find. 

But what most people don’t know is that you shouldn’t strike it too hard, because it's quite a sensitive gland and can get irritated if beaten up. Prostatitis can occur and—believe us—it is not any fun. If it does happen, then gentle manipulation is key: massaging your prostate from the outside, in, on one side (and the same on the other side). This moves the fluid into the correct place, helping release it (and the pressure) when you come. The massage also has the benefit of giving you that amazing prostatic stimulation we are all craving. It’s what makes bottoming (at least for those with a prostate) beyond worth it, so make sure you completely understand the location, along with its diverse functions.

The key to everything is understanding your anatomy, from the beautiful buttocks, to the hole it protects and everything within. The outer skin and underlying muscle is the gateway to the tube/conduit and reservoir that allows all of us the fruits of our labors. With its complete local knowledge, we can set up successful bottoming of all types. And, all the while, minimizing trauma, STDs, and over-cleaning (specifically for the every day) for the simple D-in-butt play we all love!

About the author

Dr. Evan Goldstein is the Co-Founder of Future Method and the Founder and CEO of Bespoke Surgical, the leading private practice in health and wellness for gay men. He received his MD from the University of Medicine and Dentistry School of Osteopathic Medicine. Dr. Goldstein is the go-to butt and bottoming expert, having been published in Huffington Post, Men’s Health, Healthline, and more. Learn about Dr. Goldstein by visiting his practice,

The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of Future Method, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.


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