No area of the human body has been as misconceived, misrepresented and erroneously illustrated than the female pelvis. The gynecologic view of the lithotomy position reinforces early anatomic representations of the pelvis as a bowl with a soft-tissue “floor” supporting the pelvic and abdominal viscera above. Entire professions have been built upon an archaic understanding of female pelvic anatomy that is deficient and unreliable. Astonishingly, these misunderstandings have yet to be corrected by gynecology, orthopedics, physical therapy, osteopathy or chiropractic. Is it any wonder then, that the common conditions of pelvic organ prolapse, urinary incontinence, and bowel dysfunction continue to be narrowly and unsuccessfully treated by the medical establishment? Understanding enterocele will give deeper insight into the true pelvic organ support system and why a new awareness of female pelvic anatomy is so crucial for women of all ages.
In women who have not had pelvic surgery, enterocele is a rare disorder. A quote from the gynecologic literature and a recent library search underscore this reality:
“In addition to its receiving relatively scant attention in many text books of gynaecology, there is usually no reference to the mode of presentation of an enterocele or to the methods of diagnosis. As a result, it is thought to occur infrequently.”1
Enterocele is a prolapse of the small intestine, which takes place in what is known as the cul-de-sac of Douglas. In fetal life, the peritoneum, a serous and connective tissue membrane lining the abdominal cavity, extends as a sac-like structure all the way to the perineal body between vagina and anus. This sac becomes obliterated in early life, its fused tissues forming the layers of fascia between the posterior vaginal and anterior rectal walls. When fusion of the embryonic peritoneal sac fails to occur, congenital enterocele results with a bowel-filled cul-de sac extending as far as the perineal body. Such a birth defect is a rare occurrence.
Under normal circumstances, a shallow pouch is all that remains of the embryonic sac, which is formed by the reflection of peritoneum from the anterior surface of the rectum onto the superior surface of the uterus and uppermost back vaginal wall. The uterine cervix occupies the space that was once the embryonic peritoneal sac so that the small bowel is prevented from descending between back vaginal and front rectal walls.The cul-de-sac is universally represented in gynecologic literature as projecting downward toward the pelvic “floor”. (Figure 1). The vagina is in a dependent position with the uterus and intestines sitting on top of it.
Such a conceptualization of female anatomy gave rise to the notion that the vagina must act like the trunk of a tree, a strong pedestal supporting its upper branches. This resulted in an array of highly damaging surgeries for prolapse intended to “strengthen” the vaginal walls. However, when the anatomy is rotated into its actual alignment, the cul-de-sac is located at the back instead of the bottom of the abdomen. (Figure 2)Also known as the recto-uterine pouch, the cul-de-sac is where the catheter is placed in patients undergoing peritoneal dialysis. It is known by nephrologists to exist at the back of the peritoneal cavity in both men and women and to be the most dependent portion of the cavity when the patient is in the supine position. The catheter is placed by tunneling straight through the pelvis from front to back. This would be a much more difficult procedure were the cul-de-sac located deep down into the pelvic cavity.
Forty-five degrees of rotation may not seem like much, but the consequences of such a conceptual shift are monumental. It means that the bladder, uterus and entire abdominal cavity are in a direct line with and supported by the pubic bones, rather than a pedestal-like vagina or soft-tissue “floor”. These organs are being pushed forward with every breath we take.
This reality has profound implications for women. A lifetime of habits that do not support natural pelvic anatomy are reflected in the epidemics of prolapse and bowel dysfunction seen today.
What are those habits? First and foremost is posture – the ways in which we sit, stand and move. Chronically pulling the belly in tips the abdominal cavity backward into the cul-de-sac. It is easy to visualize that over time the bowel-containing cul-de-sac may wedge further down, re-opening the embryonic rectovaginal space. Still, it would take a tremendous amount of untoward pressure to significantly deepen the cul-de-sac in a wombed woman.
It is more likely that loops of bowel chronically lodged into the deepest recess of the cul-de-sac are responsible for the chief complaint of heaviness and dragging sensation in women with posterior prolapse.
What about the woman in whom a significant enterocele has developed? First of all, she can feel this herself by placing her thumb in her vagina and ring finger in her anorectum (best done in a soothing bathtub of water). In this way the cylindrical loop of bowel is easily palpated between vaginal and rectal walls. If she feels only smooth wall layers, there is no enterocele present.
Because the uterus and cervix protect the rectovaginal space from increases in intraabdominal pressure, chronic, abnormal rises in pressure more frequently expand the anterior curve of the lower rectum into the posterior vaginal space, forming a rectocele. The rectal pocket that forms low in the back vaginal wall traps stool, causing it to swell further and eventually to obstruct defecation.
Treatment for enterocele is exactly the same as for all other prolapses, including hemorrhoids. There is a specific posture, Whole Woman® posture, that allows the abdominal and pelvic contents to be held forward. Supportive Whole Woman® exercises reinforce this natural anatomy.
Discontinuing unsound toilet habits is also critical in the prevention and treatment of prolapse and defecatory symptoms. One of the most common diagnoses in modern women is the ubiquitous “pelvic floor dyssynergia”, also called “spastic pelvic floor syndrome”, “paradoxical puborectalis” or “non-relaxing puborectalis syndrome”.
The puborectalis is the innermost portion of the levator ani muscles, which form a sling from the back of the pubic bones, around the junction between the rectum and anal canal, and back to the pubic bones. The conventional view is that this muscle is normally in a state of contraction until defecation, when the muscle relaxes and evacuation occurs. In non-relaxing puborectalis syndrome, the patient does not relax the puborectalis, but instead increases the anorectal angle, obstructing the outlet and hampering elimination.
The normal angle between anus and rectum is 90 degrees in the standing position. The anorectal angle has been found to increase (straighten) more than 30 degrees during effective straining and defecation. It is the puborectalis muscle that contracts or lengthens to close or open the anorectal angle.
The only way the puborectalis can “non-relax” is by contracting. The only way the puborectalis can “relax” is by lengthening. The pelvic diaphragm muscles work in synchrony with the abdominal muscles, contracting and relaxing in unison. When the abdominal wall is pulled in, even a little bit, the puborectalis is that much less relaxed. When the abdominal wall is fully lengthened, the puborectalis is fully relaxed, while maintaining a certain level of resting tone.
Defecation practices that make the pelvic outlet the most dependent part of the torso (sitting on a toilet seat and raising the feet on a block or stool), pulling the abdominal muscles in, or vocalizing during defecation oppose anatomically sound elimination.
Sitting on a toilet with feet on the ground, leaning forward and lifting the body weight slightly off the seat places the abdominal and pelvic organs over the pubic bones and lower belly. This alignment allows increases in intraabdominal pressure to squeeze the sigmoid colon, purging its contents into the rectal canal and out of the body. Increases in intraabdominal pressure are anatomic, and pose no threat to the vagina and rectum, which are out of the direct line of force in this position. Whereas lifting feet onto a stool and bearing down against the toilet seat allows the vagina and anorectum to take the brunt of intraabdominal pressure.
The only way the puborectalis is fully lengthened and the anorectal junction fully straightened is when the bottom is stretched out behind the body into this half-squat position. Pulling the belly in or tucking the tailbone under interferes with full relaxation and optimum sphincter release. Normal perineal descent caused by the levator ani and coccygeus muscles with effective defecation is known to be 1 to 4 cm. This is commonly called “relaxation” when more accurately it is expansion of the pelvic diaphragm under the forces of intraabdominal pressure.
Under normal conditions, these pressure increases pin the bladder, uterus and sigmoid colon against the lower belly and pubic bones, and away from the pelvic outlet at the back of the body. Considered a cause of chronic constipation, a non-relaxing puborectalis is merely a symptom of the postural mal-alignment leading to dyssynergia. Pulling the belly in and tucking the tailbone under during standing, walking and sitting chronically shortens the puborectalis so that expansion with defecation is limited.
It is self-evident that when a bowel movement is in progress it is instinctive to take a deep breath in and hold, maintaining the internal pressure that facilitates swift evacuation. This is different from “straining” where the urge, bearing down, and release sequence is prolonged or obstructed. The misguided practice of vocalizing during a bowel movement, which can only be done on the out-breath, lowers internal pressure and diminishes its role in the defecatory process. Employing ways to defecate without increasing intraabdominal pressure risks worsening symptoms of prolapse and incontinence by ignoring basic anatomic realities.
Reframing the anatomy of the cul-de-sac and the development of enterocele promotes greater understanding of pelvic organ support. The key concept is that the bladder, uterus and intestines are supported by the pubic bones and abdominal wall, and away from the pelvic “floor” at the back of the body. When the organs are carried forward, the vagina and cul-de-sac are protected against increases in intraabdominal pressure.
1 Craig C Burger G Pouch of Douglas hernia and enterocele. South African Journal of Obstetrics and Gynaecology March 2 1963