Refers to the activation (contraction and relaxation) of a muscle group. Also known as peristalsis, a peristaltic response occurs when muscles are exposed to a stimulus; it occurs in a wave.

In sexual health, peristaltic response often refers to the muscles surrounding the anus or on the pelvic floor. These muscles can experience peristalsis during sexual penetration, particularly when using prostate massagers and similar objects. Many toys are designed to cause peristalsis in order to engage and strengthen the muscle groups of the pelvic floor.