It used to be this was the thing to do then it was said this was harmful. This goes into both.

This is the first time I've learned that douching is not safe because it alters the chemical balance of the vaginal flora, which is the balance of vaginal and other organisms.

Some very insightful information about why douching can be bad for you. I'd heard this before, but this page answers some common questions and myths that plague women, concerning douching.