Ischioanal fossa
（重定向自Ischiorectal fossa）
The ischioanal fossa (formerly called ischiorectal fossa) is the fat-filled space located lateral to the anal canal and inferior to the pelvic diaphragm. It is somewhat prismatic in shape, with its base directed to the surface of the perineum, and its apex at the line of meeting of the obturator and anal fasciae.