The part of the anus that manages the delicate flow of waste which differentiates and carefully selects what shall pass based on it's current state - whether it be in solid, liquid or gas form. This
phenomenal muscle is highly used when diarrhea is present and the person is unsure if there is a liquid or gas eager to exit from the anus. In many instances it allows gas to expel while delicately
holding back a tsunami of molten fecal matter. During moments of
constipation however it remains unused.