Dr. Goldstein has postulated that chronic perineal pressure, which is pressure in the area between the vagina and the rectum, can actually cause decreased blood flow to the vagina and clitoris and can be the result of riding a bicycle.
more
here
Haven't got a clue who Dr.m Goldstein is, but the same concept is referred to in other pages as a cause of incontinence (
google).
If you're really worried about this I'd suggest you consult a physician or a bicycle specialist about a aergonomic saddle. Just say you need a good one for a hike through the mountains or something like that
