The vulva has three separate openings, and knowing which one is which matters for everything from inserting a tampon to understanding how your body works. What looks like a single area between your legs is actually three distinct passages: the urethra (for urine), the vagina (for tampons, menstrual cups, and sexual penetration), and the anus (for bowel movements). Each serves a completely different function, and mixing them up is more common than you’d think.
Three Openings, Front to Back
If you look at the vulva from front to back, the openings appear in a specific order. Near the top, just below the clitoris, is a tiny dot or slit. This is the urethral opening, the exit point for urine. It connects to a short tube, roughly an inch and a half long, that leads to your bladder. It’s small enough that many people don’t even realize it exists as a separate opening.
Below the urethra is the larger vaginal opening. This is where tampons, menstrual cups, and fingers or a penis go during penetrative sex. It’s noticeably bigger than the urethral opening and sits about 2.5 centimeters below the clitoris. Further back, past the perineum, is the anus, the external opening of the rectum.
Why So Many People Get Confused
In one study of adolescent females, only 14% could correctly identify the vagina on a diagram, and just 19% knew that urine exits through the urethra rather than the vagina. That means the vast majority of young people are navigating their own bodies without a clear map. This isn’t a personal failing. It reflects gaps in anatomy education that leave people guessing about basic biology well into adulthood.
Part of the confusion comes from the fact that the urethral opening is genuinely hard to see. It’s tiny, and the folds of the inner labia can obscure it. Many people assume there’s just one opening “down there” that handles everything, when in reality urine and menstrual blood exit from completely separate passages.
How to Find the Right Opening
A hand mirror and some privacy are all you need. Sit on the edge of a chair with your legs apart, or squat with the mirror between your feet. A flashlight can help if the lighting isn’t great. Gently spread the inner labia apart with your fingers. Pull the hood of the clitoris back slightly, and you’ll see the small urethral opening just below it. The vaginal opening is the larger one directly below that.
Getting familiar with your own anatomy this way makes inserting a tampon or menstrual cup much easier, especially the first few times. You’re aiming for the vaginal opening, not the smaller one above it.
Tampons and Menstrual Cups
Tampons and menstrual cups always go into the vaginal opening. Because urine comes from the urethra and menstrual blood comes from the vagina, these are entirely separate systems. You can urinate normally with a tampon in place. The tampon sits inside the vaginal canal and has no effect on urine flow. If you’ve ever wondered whether you need to remove a tampon to pee, you don’t.
When inserting a tampon, angle it slightly toward your lower back rather than straight up. The vaginal canal doesn’t go straight vertically. If you meet resistance or feel pain, you’re likely pressing against the wrong spot or not angled correctly. Relaxing your pelvic muscles helps the process considerably.
Sexual Penetration
During vaginal sex, the penis or toy enters the vaginal opening. The urethral opening is far too small for penetration under normal circumstances, and attempting it causes serious harm. Documented cases of urethral penetration, which are rare and typically involve unusual anatomical conditions, have resulted in urinary incontinence, chronic urinary tract infections, pelvic pain, sexual dysfunction, and tissue tears. This isn’t something that happens accidentally during typical sexual activity, but understanding the anatomy helps remove any uncertainty.
Suppositories: Vaginal vs. Rectal
Medications in suppository form go into either the vagina or the rectum depending on what they’re treating. Vaginal suppositories treat conditions like yeast infections, bacterial vaginosis, and hormonal imbalances from menopause. Some spermicide-based birth control also comes in vaginal suppository form.
Rectal suppositories go into the anus. They’re used for constipation, hemorrhoid treatment, and delivering medication to people who can’t swallow pills, such as someone experiencing nausea. The packaging will always specify which opening to use. A vaginal suppository should never go in the rectum or vice versa, since the medication is formulated for the specific tissue it contacts.
Why Anatomy Literacy Matters
Knowing your own anatomy isn’t just useful for inserting a tampon correctly. It helps you notice changes that might need medical attention, communicate clearly with a healthcare provider, and feel more confident in your body overall. The fact that most people never receive a straightforward explanation of which opening is which, and what each one does, is a gap worth closing. A mirror, five minutes, and the information above are enough to do it.