Final answer:
The septum located behind the bladder is the rectovesical septum, which separates the rectum from the bladder in males.
Step-by-step explanation:
The septum located behind the bladder is known as the rectovesical septum. This anatomical structure separates the rectum from the bladder in males. It is part of the pelvic anatomy and is significant in medical diagnoses and surgeries involving the lower abdominal and pelvic regions. The other options provided in the question (hepatorenal, splenorenal, and gastrosplenic) refer to different anatomical relationships which do not involve the bladder directly.
The bladder is a retroperitoneal organ that collects urine from the ureters. The bladder is located posterior to the pubic bone, anterior to the rectum in males, and anteroposterior to the uterus in females. The rectovesical septum is therefore positioned to separate the bladder and rectum in men.