The mesorectum is the perirectal fat that surrounds the rectum. It is not an anatomical termed recognized by the Terminologia Anatomica because it is mainly a surgical and radiological term for rectal cancer staging.
For some authors, it is the continuation of the mesocolon sigmoid.
The mesorectum begins at the rectosigmoid junction where it blends with the connective tissue of the sigmoid mesentery. It extends to the end of the rectum at levator ani.
It encloses the rectum and is limited superficially by the mesorectal fascia.
The mesorectum contains: