Prostate Position Relative to the Rectum
The prostate is located anterior to the rectum, with the posterior surface of the prostate directly adjacent to the anterior rectal wall, accessible by digital rectal examination through the anterior rectal wall. 1
Anatomical Relationship
The prostate gland sits immediately in front of (anterior to) the rectum, which is why digital rectal examination (DRE) is an effective screening tool—the examining finger can palpate the posterior surface of the prostate through the anterior rectal wall. 1 The region of the prostate adjacent to the rectal wall is where tumors commonly develop, making this anatomical relationship clinically significant. 1
Clock Position Reference
When describing locations on the prostate in relation to the rectum, the anterior quadrant is defined as the 10 o'clock to 2 o'clock position (clockwise). 1 This anterior quadrant is particularly important in rectal cancer staging, as radiologists are recommended to annotate the distance between rectal cancer and involved quadrants, especially this anterior region where the prostate is located. 1
Surgical Anatomy Considerations
During surgical procedures, the continence nerves enter the external urinary sphincter bilaterally at the 5 o'clock and 7 o'clock positions at the level of the prostatic apex. 2 This anatomical detail is relevant when considering the spatial relationship between the prostate and surrounding structures, though it describes the sphincter rather than the prostate-rectum interface specifically.
Clinical Implications
- The prostate's position directly anterior to the rectum makes DRE a standard screening method, where hard regions or asymmetry on the posterior prostate surface may indicate cancer. 1
- During prostate biopsy, transrectal ultrasound-guided approaches utilize this anatomical relationship, with systematic biopsies particularly targeting the posterior zone of the prostate. 3
- The close proximity means that rectal filling and volume can affect prostate position during radiotherapy, with the prostate demonstrating rotational movement around the left-right axis related to rectal volume changes. 4, 5