Video Clips on DVD
- 5-1
Defecography Demonstrating an Enterocele
- 5-2
Defecography Demonstrating a Sigmoidocele
- 5-3
Defect-Specific Rectocele Repair with Enterocele Repair and Vault Suspension
- 5-4
Vaginal Enterocele Repair with Rectocele Repair
- 5-5
Graft-Augmented Rectocele Repair
- 5-6
STARR Procedure
Introduction
The prevalence of constipation in North America is estimated to be between 2% and 27%. This broad range reflects a lack of agreement between how patients and physicians perceive constipation. When using standardized definitions such as the Rome criteria ( Table 5-1 ), the prevalence of constipation is estimated at 15% and half of the patients suffer from difficult evacuation of stool, known as obstructed defecation syndrome (ODS). ODS refers to a constellation of symptoms such as prolonged repeated straining at bowel movements, sensation of incomplete evacuation, and the need for digital manipulation. In a cohort of 2000 women, ages 40 to 69 years old, 60% self-reported symptoms of ODS over the last 12 months and 12% reported these symptoms weekly.
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Obstructed defecation may be due to mechanical or functional etiologies. Childbirth, hysterectomy, and chronic straining can damage the pelvic diaphragm and rectovaginal supports in women. This change results in abnormal descent of the distal rectum (leading to rectocele, intussusception, rectal prolapse); sigmoid colon (sigmoidocele); or small bowel (enterocele) causing mechanical outlet obstruction or difficulties with expulsion of stool. Functional etiologies include inefficient relaxation of striated pelvic floor muscles (multiple sclerosis, spinal cord lesions, nonrelaxing puborectalis), or inefficient inhibition of the internal sphincter muscle (short segment Hirschsprung’s, Chagas, hereditary internal sphincter myopathy). Abnormal rectal sensation refers to diminished perception of fecal contents and can lead to megarectum and fecal impaction.
Patient Evaluation
A systematic and complete pelvic floor history should be elicited on all patients with constipation. Stool consistency and frequency need to be reported even on patients who report “normal” bowel habits. The Rome criteria have been accepted as a comprehensive standardized definition for constipation but do not help to identify etiology. Obstructing colon lesions and inflammatory conditions such as inflammatory bowel disease (IBD) or diverticulitis must be excluded by colonoscopy or gastrointestinal (GI) contrast studies before considering functional etiologies. Colonic motility disorders may coexist with ODS but are more commonly associated with less than two spontaneous bowel movements per week or dependence on laxatives. Fecal symptoms associated with ODS include incomplete or unsuccessful attempts to evacuate, prolonged episodes on the toilet, rectal pain, posturing, digitations or perineal massage, bleeding after defecation, or enema dependency. Fecal incontinence to gas, liquid, solid stool, or mucus alerts the provider to possible occult rectal prolapse, anal sphincter dysfunction, or descending perineal syndrome.
Medical conditions such as diabetes, hypothyroidism, hypercalcemia, connective tissue diseases, and central or peripheral neurologic disorders may be associated with constipation. Poor diet, obesity, and sedentary lifestyle are treatable etiologies for constipation. Medication history should include prescription, over-the-counter, and herbal remedies that may have constipating or laxative properties.
Inquiries into urinary symptoms, feelings of prolapse, and sexual dysfunction should be made. We believe that it is important to identify multicompartment problems and to collaborate with urologic and gynecologic colleagues, preferably those subspecialized in pelvic floor disorders. Multicompartment surgery may be offered to selected patients. Furthermore, it is best to investigate complex pelvic floor problems before surgical intervention in order to provide the patient with realistic expectations and avoid treatment failures.
Many patients present with concomitant psychological diagnoses, and a past history of sexual or emotional abuse may be present. Appropriate mental health referrals should be made in conjunction with the evaluation and treatment of ODS.
Physical Examination
Perineal, vaginal, anal, and rectal evaluations are important components of the physical examination. Bulging of the posterior vaginal wall beyond the introitus is consistent with advanced prolapse and may represent a rectocele, enterocele, or sigmoidocele. Posterior vaginal wall prolapse is commonly associated with uterovaginal prolapse and prolapse of the anterior vaginal wall. Examination in the standing position with a finger in the rectum and vagina may be performed to elicit the maximal prolapse of the pelvic organs as they descend through the pouch of Douglas and genital hiatus. Pelvic organ prolapse can be identified on examination in the absence of complaints, and treatment should be reserved for patients with symptoms associated with prolapse such as bulging, vaginal or pelvic pressure, and the need to digitate the rectum or vagina to evacuate stool.
A gaping patulous anus may indicate neurological injury, intra-anal intussusception, or full thickness rectal prolapse. Rectal intussusception (RI) or occult rectal prolapse is an infolding of the rectal wall that can occur during defecation. The bowel wall may descend varying degrees in the rectum and anus and is thought to cause obstructive symptoms and pain by blocking the rectal ampulla or by triggering the desire to defecate. When the full thickness of the rectum extends beyond the anal verge it is known as rectal prolapse (RP). Rectal prolapse is usually associated with abnormal defecation, and both symptoms of fecal incontinence and constipation are reported. Only a few patients with internal prolapse will progress to external prolapse. When rectal prolapse is suspected but not visualized, the patient is asked to perform the Valsalva maneuver or to simulate defecation. An enema is given and the patient is asked to sit on a commode to elicit full thickness rectal prolapse. Flattening or descent of the perineum during the Valsalva maneuver beyond the ischial tuberosities is suggestive of excessive perineal descent.
Sphincter coordination is noted on anorectal examination when patients are asked to squeeze, relax, and push. Digital examination reveals resting and squeeze anal tone and a large rectocele or sphincter defect may be palpated. Anoscopy is performed to evaluate patients for mucosal abnormalities and to look for infolding of the rectum within the anal canal known as rectoanal intussusception . Colonoscopy is recommended for patients who have not undergone appropriate cancer screening to rule out anatomic lesions and inflammatory conditions.
During a gynecologic examination, evaluation of the posterior vaginal wall is performed using a single-blade speculum to retract the anterior wall and allow direct visualization of the posterior wall and fornix during rest and the Valsalva maneuver. The Pelvic Organ Prolapse Quantification (POP-Q) was developed to standardize anatomic outcomes for clinical data collection. POP-Q is validated and standardized and is the accepted staging system of prolapse by the International Continence Society and the American Urogynecologic Society. The system consists of nine points. The genital hiatus (GH) is a measurement from the urethra to the posterior vestibule of the vagina. The perineal body (PB) is measured from the posterior vestibule to the mid-anal verge. TVL is the total vaginal length ( Fig. 5-1 ). There are anterior and posterior wall landmarks. When evaluating patients with ODS, we are most interested in evaluating the posterior vaginal wall, which correlates to a rectocele and or an enterocele.
Diagnostic Testing
Laboratory testing with serum electrolyte, blood sugar levels, and thyroid function studies may help to rule out metabolic, endocrine, or organic causes. We order a thyroid-stimulating hormone (TSH) test and an ionized calcium level on patients who have not been previously evaluated. Colonoscopy is necessary to exclude malignancy or IBD. Before considering further evaluation we advocate diet modifications, exercise, and medication adjustments. A trial of a fiber supplement may be beneficial in some patients with simple constipation but can exacerbate symptoms in others. We recommend that patients increase fiber intake from natural foods up to 25 g/day over a 2-to-3-week time period to minimize adverse effects. A fiber supplement such as psyllium is suggested if dietary fiber does not relieve symptoms. When symptoms persist despite the use of fiber supplements and diet and lifestyle modification then further anorectal and radiologic studies are recommended.
Anal manometry evaluates resting and squeeze anal pressures and rectal sensory deficits. The presence of the rectoanal inhibitory reflex (RAIR) is useful to exclude Hirschsprung’s disease. Electromyography aids in the diagnosis of nonrelaxing puborectalis. Balloon expulsion is an inexpensive method to assess ability to evacuate. Defecography is the gold standard to confirm evacuatory dysfunction caused by intussusception, rectal prolapse, enterocele, sigmoidocele, rectocele, and perineal descent and is routinely ordered by the colorectal surgeon to assess the ability to empty the rectum as well as the presence and size of prolapse. (See Videos 5-1 and 5-2 for defecography demonstrating enterocele and sigmoidocele. 
) The gynecology literature endorses clinical examination as the method of diagnosis of prolapse. Defecography, however, is very useful to identify multifactorial etiologies for ODS especially when there is a discrepancy between symptoms and physical examination. Defecating magnetic resonance imaging (MRI) has advantages over traditional defecography because it involves less radiation and provides multicompartment images. However, the sitting MRI is not universally available and defecating in the supine position is not physiologic. At this time we feel that both studies have a role in diagnosing complex pelvic floor disorders: functional defecation disorders by defecography, and anterior and middle compartment pathology by the MRI.
Transit marker studies or nuclear medicine transit studies (when available) are recommended for selected patients who have infrequent bowel movements or laxative dependency to identify patients with colon dysmotility in conjunction with outlet dysfunction.
Differential Diagnosis for Patients with Constipation
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Normal motility versus colonic inertia
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Obstructed defecation
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Nonrelaxing puborectalis : Failure of relaxation of the puborectalis and external anal sphincter muscle, thus maintaining an acute anorectal angle and preventing passage of stool. Biofeedback is the preferred treatment and is superior to laxatives, fiber, and education.
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Rectal hyposensitivity/megarectum : The loss of perception of rectal contents or the rectal fullness sensation leading to fecal impaction and a dilated capacious rectum. Biofeedback and rectal irrigation with enemas are the preferred treatment.
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Hirschsprung’s disease : Aganglionosis resulting in a loss of internal anal sphincter relaxation when the rectum is distended and functional distal obstruction. This is characterized by the loss of RAIR on anal manometry. This is a congenital problem but can be diagnosed in teens and young adults and is treated by surgery.
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Nonemptying rectocele : Herniation of the rectum into the posterior vaginal wall leading to accumulation of stool in the rectocele rather than propulsion of the stool out of the anal canal. A symptomatic rectocele frequently requires digital support in the vagina or perineum and can be treated with surgery.
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Enterocele : Small bowel descent into the lower pelvic cavity leading to mechanical obstruction of the rectum. This may be an asymptomatic finding on defecography or may be associated with feelings of pressure and incomplete rectal emptying because of small bowel obstructing the rectum. This may be treated surgically.
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Sigmoidocele : Descent of the sigmoid colon into the lower pelvic cavity leading to mechanical obstruction of the rectum. This may be asymptomatic or can be associated with ODS symptoms. Treatment is surgical.
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Rectal prolapse : Internal or external rectal prolapse results in blockage of the anal canal by the protruding rectum. Internal prolapse may be occult and the rectum does not protrude beyond the anal sphincter muscles. External full thickness rectal prolapse requires surgery.
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Descending perineum syndrome : Ballooning of the perineum during the straining effort resulting in rectal pain, incomplete evacuation, and incontinence. Not all patients are symptomatic. Treatment is with biofeedback and medical management. Surgery is geared at correcting prolapse but not specifically to the descending perineum.
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Case 1, Scenario 1
The patient is a 56-year-old female, who presents with a complaint of difficulty moving her bowels and the feeling of incomplete emptying and straining. She occasionally needs to digitate inside the vagina or splint the perineum to help with fecal evacuation. The symptoms started 6 months ago but have gotten progressively worse, interfering with her work and overall well-being. She takes a fiber supplement and exercises regularly and reports soft stools daily. She denies urinary incontinence or pelvic pressure, or bulging in the vagina. She denies fecal incontinence to gas or stool. She reports a feeling of pressure and discomfort on the rectum during intercourse. Her obstetric history is significant for two uncomplicated vaginal deliveries with largest baby weighing 9 lb. She has a history of hypothyroidism for which she is being treated and routinely monitored. Her surgical history is significant for a urinary incontinence procedure 5 years ago. She takes levothyroxine sodium (Synthroid), fiber supplementation, and a multivitamin. She underwent a normal screening colonoscopy 3 months ago.
Physical findings are unremarkable. Pelvic examination reveals stage II prolapse with POP-Q point Bp ≥−1 and ≤+1. Rectal examination reveals normal appearance, neurologic examination, and sphincter tone, and a palpable rectocele is noted on rectovaginal examination. Soft stool is noted in the rectal vault. A rectocele is noted by clinical examination. The patient is also referred for anorectal testing to exclude other etiologies of ODS. Anal manometry reveals normal sphincter pressures, normal first sensation, first urge, and maximum tolerable volume. RAIR is present. The puborectalis muscles relax appropriately, and the patient is able to expel a 100-mL balloon. Defecography is consistent with a nonemptying 4-cm rectocele. Other etiologies of ODS are excluded.
Discussion of Case
A rectocele is defined as a herniation of the rectum into the posterior vaginal wall because of a defect in the rectal vaginal septum. The exact mechanism is unknown but risk factors include childbirth and chronic straining, which causes stretching and tearing of the rectovaginal support structures. A rectocele can be classified by degree of protrusion relative to the hymen on clinical examination or radiographically based on size at maximal straining. The most common surgical approaches for rectocele repair are transvaginal, transanal, or transperineal. The transvaginal approaches, namely posterior colporrhaphy or defect-specific posterior repair, are routinely performed by gynecologists, whereas the transanal or transperineal approaches are preferred by colorectal surgeons. Gynecologic indications for rectocele repair include bowel symptoms (manipulation of the vagina or perineum to defecate, incomplete rectal evacuation, and straining to defecate), lower pelvic pressure or heaviness, prolapse of posterior vaginal wall, and pelvic relaxation with enlarged vaginal hiatus. Posterior colporrhaphy or defect-specific posterior repair is frequently performed in conjunction with other vaginal prolapse and anti-incontinence procedures. Involvement of the colorectal surgeon is reserved for patients with complaints of obstructed defecation unresponsive to medical therapy. In the colorectal surgical literature indications for rectocele repair include: complaints of difficult evacuation, manual digitation, rectocele >4 cm, and residual contrast in the rectocele by defecography. Evidence of nonrelaxing puborectalis has been associated with poor functional results. Rectocele repair, regardless of the technique, reports mean improvement of 75% to 80% for bowel symptoms. There is level I evidence, however, that transvaginal repair is superior to transanal repair because of better anatomic outcomes. Traditional posterior colporrhaphy with midline rectovaginal fascia plication is the procedure of choice ( Fig. 5-2 ). Note that there are no data to support routine biologic or synthetic graft placement in the posterior vaginal wall. There is level I evidence that demonstrates superior anatomic outcomes with traditional posterior colporrhaphy and defect-specific posterior repair over defect-specific posterior repair with implantation of a cross-linked porcine small intestinal submucosa graft. Bowel and sexual function improved in all groups with no difference between groups.
