The belly button, or navel, is a scar remaining after the umbilical cord is removed at birth. While it serves no function in adulthood, its shape, whether an “innie” or an “outie,” can collect various substances. While occasional odors are common, a specific “poop-like” smell can be concerning.
Why the Belly Button is Prone to Odor
The anatomy of the belly button makes it an ideal environment for microbial growth and odors. Especially for “innies,” the navel creates a warm, moist, and dark space, shielded from light and air. This enclosed area provides a habitat for microorganisms.
Dead skin cells, sweat, lint, and skin oils accumulate within this indentation. These materials provide nutrients for bacteria and fungi on the skin. This combination allows microorganisms to multiply, leading to odors.
Understanding the “Poop-Like” Smell
The poop-like smell often comes from volatile sulfur compounds (VSCs). These compounds, such as hydrogen sulfide, methanethiol, and dimethyl sulfide, are known for their strong odors. They are metabolic byproducts of certain bacteria, particularly those that thrive in low-oxygen (anaerobic) environments.
When bacteria break down organic matter like dead skin cells, sweat, and oils, they can produce these sulfur-containing gases. This breakdown contributes to VSC formation. While common skin bacteria are present, certain anaerobic bacteria may be more prevalent in navels with strong odors.
Common Conditions Associated with the Odor
Several conditions can lead to odor-causing bacteria or foul-smelling substances. Inadequate hygiene is a common cause, as lack of cleaning allows sweat, dead skin, and lint to build up, creating a breeding ground for bacteria. This leads to odor, often resolving with improved cleaning.
Another condition is an omphalith, or navel stone. This hardened mass forms from compacted dead skin cells, sebum, and lint, resembling a blackhead. Common in deep navels, omphaliths can trap bacteria, leading to infection and odor. They may not cause symptoms until they irritate the skin or become infected.
Infections, both bacterial and fungal, are common causes of odor. Bacterial infections can present with redness, swelling, pain, and pus-like discharge that often smells bad. Fungal infections, often Candida yeast, thrive in warm, moist environments, causing a red, itchy rash, sometimes with a musty or foul smell.
Cysts can also contribute to navel odor. A urachal cyst is a rare congenital anomaly where a fetal tube connecting the bladder to the navel does not close completely. If infected, these cysts can accumulate fluid, pus, or urine, leading to leakage and a strong odor. Sebaceous cysts, from blocked glands, can also occur; if infected, they may produce a foul discharge.
Prevention and When to Seek Medical Help
Consistent hygiene prevents belly button odor. This involves daily cleaning with mild soap and water during showering. Thorough drying afterward, especially for “innies,” is important to prevent moisture buildup and microbial growth. Avoiding excessive lotions or creams also helps prevent bacterial or fungal growth.
While many odors resolve with simple cleaning, certain signs indicate a need for medical attention. Consult a doctor if odor persists or worsens despite cleaning. Other signs include redness, swelling, pain, or warmth around the navel. Pus-like, bloody, or discolored discharge, fever, or a lump in the area also warrant medical evaluation. A healthcare provider can diagnose the cause (infection, cyst, or omphalith) and recommend treatment, such as antibiotics, antifungals, or surgery.