To assess the degree of dysfunction, three measurements must be taken into account. First, an anatomic landmark known as the pubococcygeal line must be determined, which is a straight line connecting the inferior margin of the pubic symphysis at the midline with the junction of the first and second coccygeal elements on a sagittal image. After this, the location of the puborectalis muscle sling is assessed, and a perpendicular line between the pubococcygeal line and muscle sling is drawn. This provides a measurement of pelvic floor descent, with descent greater than 2 cm being considered mild, and 6 cm being considered severe. Lastly, a line from the pubic symphysis to the puborectalis muscle sling is drawn, which is a measurement of the pelvic floor hiatus. Measurements of greater than 6 cm are considered mild, and greater than 10 cm severe. The degree of organ prolapse is assessed relative to the hiatus. The grading of organ prolapse relative to the hiatus is more strict, with any descent being considered abnormal, and greater than 4 cm being considered severe.
The pelvic floor is a combination of multiple muscles with ligamentous attachments creating a dome-shaped diaphragm across the boney pelvic outlet. This complex of muscles spans from the pubis (anterior) to the sacrum/coccyx (posterior) and bilateral to the ischial tuberosities. The bulk of the pelvic musculature is the levator ani, composed of the puborectalis, pubococcygeus, and iliococcygeus. The puborectalis wraps as a sling around the anorectal junction accentuating the anorectal angle during contraction and is a primary contributor to fecal continence. Elevation and support of the pelvic organs are associated with the pubococcygeus and the iliococcygeus. The pubococcygeus is the most medial component which separates, fashioning the levator hiatus with openings for the urethra, vagina (females), and anus. The bulbospongiosus and ischiocavernosus muscles are the primary contributors to the superficial portion of the anterior pelvic floor. The more superficial musculature of the posterior pelvic floor constitutes the external anal sphincter. The transverse perineal muscles cross the mid-portion of the superficial aspect of the pelvic floor and coalesce with the bulbospongiosus muscles and external anal sphincter as the perineal body.
Pelvic floor dysfunction is very different than pelvic organ prolapse. Pelvic organ prolapse happens when the muscles holding a woman’s pelvic organs (uterus, rectum and bladder) in place loosen and become too stretched out. Pelvic organ prolapse can cause the organs to protrude (stick out) of the vagina or rectum and may require women to push them back inside.
Pelvic floor dysfunction can be diagnosed by history and physical exam, though it is more accurately graded by imaging. Historically, fluoroscopy with defecography and cystography were used, though modern imaging allows the usage of MRI to complement and sometimes replace fluoroscopic assessment of the disorder, allowing for less radiation exposure and increased patient comfort, though an enema is required the evening before the procedure. Instead of contrast, ultrasound gel is used during the procedure with MRI. Both methods assess the pelvic floor at rest and maximum strain using coronal and sagittal views. When grading individual organ prolapse, the rectum, bladder and uterus are individually assessed, with prolapse of the rectum referred to as a rectocele, bladder prolapse through the anterior vaginal wall a cystocele, and small bowel an enterocele.
Mechanistically, the causes of pelvic floor dysfunction are two-fold: widening of the pelvic floor hiatus and descent of pelvic floor below the pubococcygeal line, with specific organ prolapse graded relative to the hiatus. Associations include obesity, menopause, pregnancy and childbirth. Some women may be more likely to developing pelvic floor dysfunction because of an inherited deficiency in their collagen type. Some women may have congenitally weak connective tissue and fascia and are therefore at risk of stress urinary incontinence and pelvic organ prolapse.
By definition, postpartum pelvic floor dysfunction only affects women who have given birth, though pregnancy rather than birth or birth method is thought to be the cause. A study of 184 first-time mothers who delivered by Caesarean section and 100 who delivered vaginally found that there was no significant difference in the prevalence of symptoms 10 months following delivery, suggesting that pregnancy is the cause of incontinence for many women irrespective of their mode of delivery. The study also suggested that the changes which occur to the properties of collagen and other connective tissues during pregnancy may affect pelvic floor function.
Increases bladder and bowel control. The pelvic floor muscles are directly responsible for controlling urine and bowel movements. If these muscles are weak, you’re more likely to experience constipation, urinary incontinence, struggle to control flatulence, or experience urine leakage from forceful activities like when sneezing, coughing, or laughing (called “stress incontinence”). Strengthening your pelvic floor can improve your bowel and bladder control.