The aim of the study was to analyse the dynamic anatomical supports of the posterior vaginal wall from the perspective of rectocele and rectal intussusception repair. Two groups of patients were studied. Group 1 (n = 24) with genuine stress incontinence but no major vault prolapse had vagino/proctomyograms and transperineal ultrasound examinations. Group 2 with vaginal vault prolapse, clinical rectoceles and obstructive defecation symptoms (n = 19 had single-contrast defecating proctography before and after posterior-sling surgery. The posterior vaginal wall is suspended between perineal body, which underlies half its length, and uterosacral ligaments, which also support the anterior wall of rectum. Muscle forces stretch the vagina and rectum against the perineal body and uterosacral ligaments, creating shape and strength, like a suspension bridge. Postoperative proctogram studies indicated that anterior rectal wall intussusception has the same etiology as rectocele, deficient recto-vaginal ligamentous support. Repair to uterosacral ligaments and perineal body should be considered with large rectoceles, anterior rectal wall intussusception and obstructive defecation disorders.