Pelvic organ prolapse occurs when the pelvic floor muscles become weak or damaged and can no longer support the pelvic organs. There are a number of different types of prolapse that can occur in a woman's pelvic area. These are divided into three categories according to the part of the vagina they affect: front wall, back wall or top of the vagina. It is not uncommon to have more than one type of prolapse.
Prolapse can occur as a result of several factors, including vaginal child birth, advancing age and obesity. Vaginal delivery, hysterectomy, chronic straining, normal aging and abnormalities of connective tissue or connective-tissue repair predispose some women to disruption, stretching or dysfunction of the connective-tissue attachments of the vagina, resulting in prolapse.
Four main types of pelvic organ prolapse can occur:
- Cystocele (bladder prolapse) - when the bladder prolapses, it falls towards the vagina and creates a large bulge in the front vaginal wall. This is called a cystocele and is the most common type of prolapse in women.
- Urethrocele (prolapse of the urethra) - when the urethra (the tube that carries urine from the bladder) slips out of place, it also pushes against the front of the vaginal wall, but lower down, near the opening of the vagina. This usually happens together with a cystocele (see above).
- Enterocele (prolapse of the small bowel) - Part of the small intestine that lies just behind the uterus (in a space called the pouch of Douglas) may slip down between the rectum and the back wall of the vagina. This often occurs at the same time as a rectocele or uterine prolapse.
- Rectocele (prolapse of the rectum or large bowel) - This occurs when the end of the large bowel (rectum) loses support and bulges into the back wall of the vagina. It is different from a rectal prolapse (when the rectum falls out of the anus).