Over the years, I have found that many people aren't aware that soap should not be used to clean the vaginal opening, the tip of the penis (urethral opening), or the anal sphincter.

Regularly applying soap to these areas can cause the mucosal lining in these areas to become dry and unhealthy. A chronically dry mucosal lining can lead to a number of uncomfortable health conditions, such as anal fissures, lichen sclerosus, chronic inflammation, and a tendency to experience infections.

If you use soap to clean your body, you should limit its contact to your skin. Your skin is lined with sebaceous glands that secrete an oily substance called sebum, which serves to keep your skin waterproof and resistant to infection by undesirable microorganisms.

Typically, the presence of sebum prevents soap from drying out skin to a point where significant health challenges can arise. Still, unless you work with grease and oil, it's best to use soap sparingly - just enough to remove objectionable odors and to feel clean and refreshed.

The mucosal linings of the vaginal opening, the penile opening, and the anal sphincter don't secrete sebum to offer protection against the drying effects of soap. Actually, the labia minora does contain some sebaceous glands, but in most women, there aren't nearly enough sebaceous glands in this region to keep the vaginal opening healthy if regularly washed with soap.

So how do you wash the vaginal opening, the penile opening, and the anal sphincter? Ideally, with warm or hot water. And when more intense cleaning is desired, you can use warm or hot salt water.

I've worked with enough people who have experienced health challenges from using soap in the private areas to know that this advice is worth heeding. Please share this information with family and friends, as my experiences have led me to believe that most people aren't aware of this issue.

Addendum on November 9, 2008:

This health tip is especially important for parents whose children are still young enough to require help with bathing. I've encountered a number of cases where regular use of soap on the mucosal linings in a child's private areas has created chronic irritation, almost always with the parent(s)and child involved being unaware of this connection.

In my opinion, avoiding soap when cleaning a child's private areas is essential guidance that all new parents should receive, as infants and some toddlers can't clearly signal discomfort in these areas, and in many such cases, I suspect that the source of the child's discomfort is never identified.

Addendum on October 6, 2009:

From Our Mailbag:

Good morning Dr. Kim,

One quick question with respect to Dr. Ohhira's Probiotic Soap - In the back of my mind when I was reading (about it) was your mention in an article some time back about avoiding the use of soaps on private parts, so my question is:

Can this soap be used over the ENTIRE body (from head to toe) without exception? I would appreciate clarification on this.

Susan S.

Canada

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Dear Susan,

Though Dr. Ohhira's probiotic soap is more mild than the vast majority of commercial bar soaps on the market, I still don't recommend using it regularly on the anal sphincter area or so that it comes into regular contact with the inner walls of the vagina or the urethra in males and females.

(The urethra is the tube through which urine exits the body.)

These areas have specialized mucosal linings that shouldn't be dried out with any type of soap - warm or hot water is all that should be used in these areas.

The rest of one's private areas can be washed with soap without ill effects. It's the mucosal lining that is inside of the areas mentioned above that should be protected.

If the anal sphincter is washed with a mild soap, then one can apply some natural moisturizer to this area right after washing - coconut oil or something similar works well for this purpose. In fact, for clients who are suffering with an anal fissure, I regularly recommend application of coconut oil to the anal sphincter three or more times a day.

I hope this helps.

Ben Kim