The vagina is really a muscular tube and when women are not menopausal, it is rich in blood flow, it is pink in colour, and it has collagen, which are certain cells that bring strength to tissue. It has glandular cells or tissue that produce moisture which all help with lubrication for intercourse.
Vaginal tissue, like the skin, changes over time when the collagen support fibers lose their youthful strength and vitality. With the normal aging process or physical stresses from childbearing, the tissue can become stretched and weakened. The result is a feeling of vaginal looseness called laxity, the side effects of which can be diminished physical sensation during intercourse and urinary incontinence.
When women go through menopause it changes the vagina when it loses the estrogen. It starts to lose the integrity and starts to lose the blood flow, it changes its colour, it becomes paler, and it stops producing the healthy kind of lubrication that is required for healthy intercourse.