A belly button that smells foul, even fecal, is almost always caused by trapped bacteria feeding on dead skin, sweat, and oil inside the navel. The belly button is a warm, dark, moist fold of skin that rarely gets direct cleaning, making it an ideal breeding ground for odor-producing microorganisms. The good news: most causes are fixable with better hygiene. A few, though, signal something that needs medical attention.
Bacteria and Trapped Debris
Your belly button collects sebum (the oil your skin naturally produces), dead skin cells, sweat, lint from clothing, and even hair. Bacteria break down this mix of organic material, and the byproducts of that process can smell remarkably like feces. Deep “innie” belly buttons are especially prone because they trap more debris and get less airflow, letting bacteria multiply undisturbed for days or weeks between cleanings.
Over time, if this buildup is never cleared out, it can harden into what’s called a navel stone. These consist of compacted hair, bacteria, keratin, and sebum. The visible surface of a navel stone is often dark brown or black from oxidized fatty acids and melanin. Navel stones can go unnoticed for years and produce a strong, persistent smell even in people who otherwise shower regularly, because a quick rinse in the shower doesn’t dislodge something that’s essentially cemented in place.
Yeast and Fungal Infections
Candida, the same yeast behind most vaginal yeast infections and oral thrush, can overgrow inside the belly button. On its own, a yeast infection doesn’t always produce a strong odor. But when it develops alongside a condition called intertrigo, where heat, moisture, and skin-on-skin friction combine, you can get a musty or sour smell that intensifies over time. People with deeper navels, larger body size, or who sweat heavily are more susceptible.
Antibiotics can also set the stage for yeast overgrowth by killing off the normal bacteria that keep Candida in check. If your belly button started smelling during or after a course of antibiotics, a yeast infection is a likely culprit. Look for redness, itching, or a white, cottage cheese-like discharge as telltale signs.
Skin Conditions in the Navel
Psoriasis and eczema both commonly affect the belly button. Psoriasis produces thick, flaky patches of skin that can trap moisture underneath, while eczema causes cracking and weeping that creates a wet environment bacteria love. Both conditions accelerate the buildup of dead skin inside the navel, and both can cause secondary bacterial infections when the skin barrier breaks down. If you already have psoriasis or eczema elsewhere on your body (scalp, elbows, knees, behind the ears), your belly button smell may be connected.
Infected Piercings
Belly button piercings take 12 to 18 months to fully heal, and some tenderness, redness, and crusting is normal during that window. Infection is a different story. The key signs: painful swelling or warmth at the site, increasingly red or discolored skin, and discharge that’s yellow, green, gray, brown, or bloody. If the discharge smells bad, that strongly suggests infection rather than normal healing. An untreated piercing infection can progress to an abscess, a pocket of pus that requires drainage.
How to Clean Your Belly Button Properly
Most smelly belly buttons improve dramatically with intentional cleaning, not just letting shower water run over them. Here’s what works:
For an innie: lather a cotton swab or the corner of a washcloth with mild, fragrance-free soap and warm water. Gently work it into the folds of your belly button to lift out debris. When you’re done, use a dry cotton swab or clean towel corner to dry the inside thoroughly. Moisture left behind feeds the same bacteria you’re trying to remove.
For an outie: use your hands or a washcloth with mild soap, lather the area, rinse, and dry completely.
A few things to avoid: don’t scrub aggressively, because small tears in the delicate skin inside the navel give bacteria a direct route to cause infection. Don’t apply body lotion inside your belly button. The navel is already a naturally moist environment, and adding lotion increases bacterial growth. Stick to soap and water. That’s genuinely all you need.
Signs That Something More Serious Is Going On
A smell that doesn’t improve after a week or two of consistent cleaning deserves a closer look. Yellowish or greenish discharge, skin that feels thick or hardened around the navel, persistent redness, or pain when you touch the area all point toward a bacterial infection that may need treatment. Persistent wetness or drainage from the belly button that never fully dries, particularly if it’s been present since childhood, can occasionally indicate a urachal remnant, a structural issue where tissue from a fetal connection between the bladder and the navel didn’t fully close. This is uncommon but diagnosable with an ultrasound, MRI, or CT scan.
If the smell appeared suddenly, comes with discharge you haven’t seen before, or is accompanied by fever, those are reasons to get it evaluated rather than continuing to clean and wait.