After the epidural is placed in the dilation phase of labor, the woman gradually feels relief from the pain. After 15-20 minutes, the epidural has taken effect and the woman feels no pain at all.
On the other hand, the woman does have sensations and can feel the contractions as pressure. She may also notice that the baby slips through the birth canal until it is expelled, but she does not feel pain in the walls of the vagina. All of this will depend on the dose of anesthesia, which can be regulated at different times during the delivery.