Diagnostic Approach to Posterior Compartment Pelvic Floor Disorders

Primary Diagnostic Considerations

The American College of Radiology guidelines note that rectoceles are structural defects of the rectovaginal septum, not mucosal abnormalities, and normal endoscopy is expected 1, 2
Approximately one-third of patients with posterior vaginal wall bulging have rectoceles, which present with bulging of the posterior vaginal wall requiring manual pressure (splinting) to evacuate stool 1
The ACR guidelines specifically state that rectoceles require imaging (not endoscopy) for diagnosis, and fluoroscopic cystocolpoproctography (defecography) is the initial imaging test of choice 1, 2

Defecography has a sensitivity of 94% for rectoceles and 88% for internal rectal prolapse, and directly visualizes the defecation process and identifies structural abnormalities that physical examination misses 1
Defecography can differentiate rectocele from enterocele/sigmoidocele, which both present with posterior vaginal bulging, and detects clinically occult abnormalities 1, 2

Structural pelvic floor disorders (rectocele, intussusception, enterocele) are mechanical/positional problems, not mucosal pathology, and endoscopy evaluates the mucosal surface but cannot assess the dynamic function or structural support of the pelvic floor 1, 2
Manual pressure toward the vaginal wall to facilitate defecation is pathognomonic for posterior compartment prolapse, and this finding strongly suggests either rectocele or occult rectal prolapse 1