A fecal incontinence device for insertion into a vagina, comprising: a plurality of shell segments, which together form an enclosed cylinder with rounded ends in a collapsed state of the device, wherein one of the cylindrical shells is disposed in the device facing a posterior wall of the vagina when the device is inserted into the vagina； a pressure generating structure attached to and abutting the posterior-facing cylindrical shell； and, a state-changing mechanism configured to reversibly transition the device from the collapsed state to an expanded state.
