A probe including a housing, a rectal muscle air bag, a rectal tube, an anal muscle air bag, and an anal tube is provided. The rectal muscle air bag mounts to the housing a first distance from a non-insertion end. A rectal tube is connected to the rectal muscle air bag at a first end and to a first pressure sensor at a second end. The anal muscle air bag is mounted to the housing a second distance from the non- insertion end. The anal tube is connected to the anal muscle air bag at a first end and to a second pressure sensor at a second end. The first distance is selected to position the rectal muscle air bag adjacent a rectal muscle, and the second distance is selected to position the anal muscle air bag adjacent an anal muscle when the housing is inserted in the rectum.
