Anal Sex: Why Does It Hurt?
by Allison Danish, MPH
Anal sex! It’s happening aaaall around us. And has probably been happening since the dawn of buttholes—just look at this pottery from Ancient Greece. While it’s grown more visible in popular culture in the past few decades, and potentially more people are having anal sex than they have in centuries, we don’t talk about it that much. And what we really don’t discuss is pain with anal sex—anodyspareunia. It’s a silent but(t) oftentimes expected outcome of having anal—so… let’s talk about it! What's the science behind why it happens? How common is it? And what can we do about it?
Let’s dig in.
Who’s having anal sex?
There’s a common misconception that anal sex only happens between cis gay men (and sex-starved teenagers, but that’s a different conversation).
In reality, 35.9% of cis women and 42.3% of cis men have had anal intercourse with other-sex partners (Herbenick 2015). And a large European study and a small North American survey have estimated that about 85% of cis men who have sex with men (MSM) have had anal sex with a same-sex partner in the past year (EMIS 2011, Bespoke Surgical 2018).
Frustratingly, we’ve yet to find any definitive studies determining how often cis women who have sex with women have anal sex and how often trans and nonbinary folks are having anal sex. So, unfortunately these folks won’t be included in the numbers below—but the reasons why it can be painful as well as the tips and tricks for making it comfier are pretty universal—so stick around!
Anyway, suffice it to say: lots of people are doing butt stuff, and it’s not just gay men.
How often does anal sex hurt?
In a recent study among cis men and women in the United States, 15% of cis men and 72% of cis women indicated some pain during their last sexual experience that involved anal intercourse with an other-sex partner (Herbenick 2015). Men were most likely to experience pain on their penis or inside their urethra, and women are most likely to experience pain around their anal opening.
Among men who have sex with men, studies have estimated that 14-61% experience pain with receptive anal sex (Damon 2005, Rosser 1997, Rosser 1998, Vansintejan 2013).
Why does anal sex hurt?
That’s a more complicated question to answer. Similar to dyspareunia (pain with vaginal sex), anodyspareunia has a whole lotta potential causes. Time to put on our research hats.
Butts don’t make lube. Bum-mer. This means there can be friction during anal sex that can make things uncomfortable and sometimes cause anal fissures (tiiiny little butthole cuts).
The Usual Suspects
As discussed in Why is Sex Painful Pt. I and II, things like endometriosis, infections, and interstitial cystitis/painful bladder syndrome can also contribute to pain during anal sex. Pelvic organs (the uterus, bladder, prostate, and rectum) are close neighbors—think of them like townhouses or newly constructed suburban homes—that are all supported by your pelvic floor. When one or more organs are affected by an infection or another medical condition, things might get a little uncomfortable when you introduce an object into your rectum. That object squishes your other organs, muscles, and connective tissues around, so if they’re inflamed or the muscles are tight or bound up by adhesions, it makes sense that it might hurt!
A Cranky Pelvic Floor
We’ve got a whole lot of muscles downstairs. And some of these make up and support the anorectum, which you can think of as the butthole + your rectum (where poop is stored until you make a bathroom trip. A poop detainment center, if you will). These muscles, like a lot of other muscles in our bodies, can get tight and short. This means they have less range of motion, which can make it uncomfortable to stretch them further than they want to go. Think of it like trying to touch your toes when your hamstrings are sore.
People can develop tight, cranky pelvic floors for tons of reasons. Scientists are thinking it could be a couple of things:
- Chronic voluntary holding of pee and poop—especially if you’ve started to develop any pain with sex, which can reinforce the constant holding of these pelvic floor muscles
- Injury or trauma (from pelvic surgery to birth injuries to sexual abuse or assault, etc.)
- Pain syndromes like endometriosis and irritable bowel syndrome
- Musculoskeletal quirks. Asymmetrical bones, funky ways of standing or walking, or prolonged sitting may put stress on the pelvic floor (Faubion 2012)
Sometimes dick is too big, and this could mean more friction or discomfort with deep penetration. The anorectum (butthole + poop detainment center, see Figure 1.) is about 22 - 25cm (about 8.5 - 9.5 in) long, varies in diameter, and is a little curvy (Kenig 2013). The rectum (just the poop detainment center) has the ability to stretch. A lot. But the preferred size of the organ or toy doing the penetrating varies widely. And although genital fit is cited as a reason why anal sex is painful in a few studies, the mechnism for why that is… is still kind of a mystery. It could be that some buttholes are tighter than others, or the anorectal angle (the bend between the anal canal and the rectum) is a little too acute or sharp (see Figure 2.).
Figure 1. The anorectum. Anorectal Anatomy and Physiology, Torre et al. 2016.
Figure 2. MRI of anorectal angle variations. MRI of the Pelvic Floor and MR Defecography, Maccioni and Alt, 2018.
The prostate is a neat little gland that hangs out in front of the rectum and makes fluid that feeds and protects sperm once they’re out in the great, big world. The prostate can become infected (called prostatitis)—which causes the gland to become inflamed and… well, it hurts. It’s a really common source of urinary tract infections for people with prostates. Sometimes prostatitis is caused by bacteria, while chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a little more mysterious. It’s estimated to affect 10-15% of people with prostates and accounts for 90% of prostatitis cases. Scientists currently theorize that CP/CPPS is caused initially by an event that creates inflammation or damage to the nerves in and around the prostate (this could be infection, trauma, an allergy, dysfunctional peeing, etc.), and then the nervous system starts to become hypersensitive to pain, or starts feeling pain in uninjured areas or in response to feelings that wouldn’t normally be painful. (Nickel 2009) This is called peripheral and eventually central sensitization. (Latremoliere 2009)
Prostatitis can cause pain in the lower belly, the perineum (taint), penis, scrotum, and lower back. With CP/CPPS, it takes an average of 87 weeks to diagnose even though it takes a big toll on quality of life. (Smith 2016) And we’re pretty angry about that.
Cancer & Prostatectomy
Sometimes part of or all of the prostate needs to be removed to prevent the spread of prostate or other kinds of pelvic cancers. A prostatectomy may also need to be performed if someone has an enlarged prostate or has severe urinary symptoms like urinary retention. Removal of the prostate may make receptive anal sex less pleasureable, and radition from cancer treatment can damage the rectum and anus, making receptive anal sex painful. Cancer treatment and prostatectomy can also lead to hormonal and anatomical changes that can affect someone’s overall sexual functioning, from erectile dysfunction to decreased libido. (Cheng 2021)
Hemorrhoids, Fissures, and Fistulas—Oh, My!
Hemorrhoids are swollen veins in the anus and lower rectum. About 75% of adults will experience this at some point. Some potential causes include straining on the toilet, chronic diarrhea or constipation, pregnancy, obesity, regularly lifting heavy stuff, and having anal sex ¯\_(ツ)_/¯ This can mean having (bright red) blood in your poops, pain or discomfort, itching or irritation, and inflammation.
Fissures are little cuts on the anus, usually caused by hard or large poops or sometimes having anal sex.
Brace yourselves for this one. Bodies are absolutely remarkable. Anal fistulas happen when anal glands (located just inside the anus) become infected, forming an abscess (a swollen pocket of pus). This abscess can then, if it is drained (either on its own or surgically), form a little tunnel from the anal gland to the skin around the anus. Fistulas are basically like tiny extra buttholes. The cute little extraneous buttholes can be very painful and can cause swelling around the anus.
To wrap up this section: very bad things can happen to our buttholes, and if we try to have anal sex while experiencing any of the above, it’s likely to be a little rough.
IBS & IBD
IBS, or irritable bowel syndrome, is a condition that affects the large intestine and can cause cramping, diarrhea and/or constipation, and bloating.
Inflammatory bowel disease, or IBD, comes in two primary flavors: Crohn’s disease and ulcerative colitis. They essentially cause inflammation in the lower intestine (and the formation of sores, if we’re talking ulcerative colitis), which can then cause diarrhea, pain, and fatigue.
To our knowledge, there are no studies linking IBS and IBD to pain with anal sex, but there are studies connecting the two to pain with vaginal sex (Choung 2010, Rosenblatt 2015). Vaginas and rectums live in the same neighborhood (and IBS and IBD are disorders of the large intestine after all), so we’re going to go out on a limb here and say IBS and IBD may contribute to pain during anal sex. And it makes sense! Abdominal and gastrointestinal inflammation and distress may equal a less-than-stellar anal sex-perience.
How can I make anal sex more comfortable?
Anodyspareunia is super common, but that doesn’t mean it’s inevitable! Try these tips and tools below if anal sex is sometimes painful for you:
- Use lube that’s designed for your butt!
- Go slow—it’s not a race, friends.
- Ease into it with fingers or oral stimulation (dental dams recommended)
- Dilate with a butt plug! Check out these great options from b-Vibe.
- If anal feels too deep or it feels like there’s a lot of friction, add Ohnut into the mix!
- Relax your pelvic floor muscles with Pelvic Gym.
- If pain or discomfort persists, see a physician or a pelvic floor physical therapist.
Final friendly reminder: sex doesn’t have to be painful—and anal sex is no exception. Take it easy, be gentle with yourself and your partner(s). Remember to use condoms and dental dams, which is particularly important with the butt, because our tissue there is more fragile and susceptible to infection. If you’re having sex with a toy, be sure to use something with a base because your butt is in fact a magician and can and will make things disappear. And nobody wants to make that particular trip to the emergency room.