Medical & Surgical Management of Pelvic Floor Disorders Affecting Defecation

Abstract

Pelvic floor disorders that affect stool evacuation include structural (example: rectocele) and functional disorders (example: dyssynergic defecation). Meticulous history, digital rectal examination, and physiological tests such as anorectal manometry, colonic transit study, balloon expulsion and imaging studies such as anal ultrasound, defecography, and static and dynamic MRI can facilitate an objective diagnosis and optimal treatment. Management consists of education and counseling regarding bowel function, diet, laxatives, most importantly behavioral and biofeedback therapies, and lastly surgery. Randomized clinical trials have established that biofeedback therapy is effective in treating dyssynergic defecation. Because dyssynergic defecation may co-exist with conditions such as solitary rectal ulcer syndrome (SRUS), and rectocele, before considering surgery, biofeedback therapy should be tried and an accurate assessment of the entire pelvis and its function should be performed. Several surgical approaches have been advocated for the treatment of pelvic floor disorders including open, laparoscopic and trans-abdominal approach, stapled transanal rectal resection (STARR), and robotic colon and rectal resections. However, there is lack of well controlled randomized studies and efficacy of these surgical procedures remains to be established.

Introduction

Pelvic floor disorders are common and cause significant bowel problems. The pelvic floor is a complex muscular apparatus within the pelvis and serves defecation, micturition, and sexual function. The most common pelvic floor disorders are fecal and urinary incontinence and pelvic organ prolapse. Approximately 23.7% of women have at least one pelvic floor disorder and 2.9% pelvic organ prolapse¹.

Here, we focus on recent advances in the management of pelvic floor disorders affecting defecation, with a brief overview of pathophysiology and diagnosis. These disorders affect both women and men and necessitate a multidisciplinary team approach involving colorectal surgeon, gastroenterologist, pain specialist, physical therapist, radiologist, urogynecologist, and urologist.

Pelvic Floor Anatomy and Normal Physiology

The pelvic floor has superficial and deep muscle layers that interlace and envelope the rectum, bladder and uterus. The superficial layers include the internal anal sphincter (IAS) and external anal sphincter (EAS), perineal body, and transverse perinei muscles². The deeper pelvic muscles, also known as levator ani, consist of the pubococcygeus, ileococcygeus, and puborectalis. The puborectalis maintains anorectal angulation and creates a mechanical barrier for stool flow and maintains pelvic floor integrity and its disruption/dysfunction may cause common pelvic floor disorders^3,4. The pelvic floor receives nerve supply from the pudendal and perineal nerves and sympathetic and parasympathetic nerves. Branches from the sacral nerve roots of S2, S3, and S4 innervate the pelvic floor muscles. The puborectalis muscle (middle layer of pelvic floor muscle) is actually innervated by the pudendal nerve and the deep muscles (pubococcygeus, ileococcygeus, and coccygeus) are innervated by the direct branches of sacral nerve roots S3 and S4.^[3] Pudendal nerve damage may cause dysfunction of puborectalis muscle and EAS muscles (both constrictor muscles) and this in turn may cause fecal incontinence. During normal defecation, the voluntary effort of bearing down increases the intra-abdominal pressure, together with the contraction of the rectum and perineal muscles. Simultaneously, the anal sphincters and puborectalis relax, the anorectal angle widens, and the perineum descends. These sequential movements facilitate the movement of stool from the rectum resulting in stool evacuation. (Figure 1).

Figure 1.

A. Diagram of a coronal section of the rectum, anal canal, and adjacent structures. The pelvic barrier includes the anal sphincters and pelvic floor muscles. “Reprinted from Gastroenterology, 124, Bharucha, Fecal Incontinence, 1672-1685, 2003, with permission from Elsevier.”

B. Sympathetic, parasympathetic, and pudendal nerve supply to the anorectum. “Reprinted from Peripheral Neuropathy, 4_th edition, Bharucha and Klingele, Autonomic and Somatic Systems to the Anorectum and Pelvic Floor, 279–298, 2005, with permission from Elsevier.”

Dyssynergic Defecation

Dyssynergic defecation (DD) is characterized by paradoxical anal contraction, inadequate anal relaxation, and/or impaired push effort caused by incoordination of abdominal, rectal, and anal muscles⁵. The most common symptoms are excessive straining (84%), feeling of incomplete evacuation (76%), abdominal bloating (74%), passage of hard stools (65%) and less than 3 bowel movements per week (62%). Digital maneuvers are frequent (~35%), although infrequently reported⁶.

Diagnosis

The diagnosis of DD requires fulfillment of symptomatic (Rome III) and manometric criteria, with one other quantifiable measure of abnormal defecation such as abnormal balloon expulsion test (BET), prolonged delay in colonic transit, or incomplete evacuation during defecography⁹.

Digital rectal exam (DRE)

Digital rectal exam (DRE) is a useful bedside screening tool. The exterior inspection can detect skin excoriation, squamous cell cancer, skin tags, anal fissures, fistulas or hemorrhoids. The perineal sensation (to exclude neuropathy) is evaluated by gently stroking the perianal skin with a cotton bud in all four quadrants.

Digital penetration may reveal a stricture, spasm, tenderness, mass, blood or stool. If there is a lack of awareness of stool in the rectum this may suggest rectal hyposensitivity. Primarily, the resting tone is evaluated, followed by asking the subject to squeeze it is possible to evaluate the anal sphincter and puborectalis muscle. The patient is asked to push and bear down as if to defecate, and during this maneuver, the examiner should perceive relaxation of the external anal sphincter and/or the puborectalis muscle, together with perineal descent. An absence of these normal findings should raise the index of suspicion for an evacuation disorder such as dyssynergic defecation. DRE has a sensitivity of 77% and specificity of 87% for detecting dyssynergia⁷, but is infrequently performed, even by gastroenterologists, and there is lack of training⁸.Thus, a concerted effort is needed to improve the training of digital rectal examination.

Anorectal manometry (ARM)

This test provides information regarding rectal and anal pressures at rest and during simulated defecation. During rectal balloon distention it provides information regarding rectal compliance and sensation, and recto-anal reflexes¹⁰. Normal subjects can exhibit dyssynergia when attempting to defecate in the left lateral position; hence manometric changes are best assessed with the patient on a commode and with a sensation of stooling^{11, 12}. The best method to diagnose dyssynergia is to distend a balloon in the rectum and ask the subject to attempt evacuation in a sitting position^13,14. Four patterns of dyssynergia have been described, and their identification helps tailor biofeedback therapy. Type I is adequate push effort with paradoxical anal contraction, type II is impaired push effort with paradoxical anal contraction, type III is impaired anal relaxation with adequate push effort, and type IV is impaired push effort with impaired anal relaxation. These patterns were established with the conventional manometry, which is very useful and still widely used in many centers. The new HRM system, (Sierra Scientific Instruments, Los Angeles, CA) allows interpolation of manometric recordings from 12 circumferential pressure sensors into a detailed topographical plot. This system can provide a greater resolution of the intraluminal pressure changes with more anatomical detail, hopefully leading to a better assessment of common pelvic floor disorders¹⁵. (Figures 2A, 2B)

Figure 2.

A: HRM image of a healthy control showing manometric and topographic features during an attempted defecation maneuver. The upper part of the panal shows pressure changes from the rectum indicating that subject generated a good push effort. The lower part of the panel shows topographic images from the entire anal canal and puborectalis showing that both the anal sphincter and puborectalis relaxed normally with a significant drop in pressure. The location of sensors from the anal verge and the pressure gauge as represented by the various colors are also shown.

B: HRM image of a patient with constipation showing manometric and topographic features during two attempted defecation maneuvers. The upper part of the panal shows pressure changes from the rectum indicating that patient generated a good push effort. The lower part of the panel shows topographic images from the entire anal canal and puborectalis showing that both the anal sphincter and puborectalis exhibited paradoxical anal contraction, typical of dyssynergic defection. The location of sensors from the anal verge and the pressure gauge as represented by the various colors are also shown.

Balloon Expulsion Test

This provides information regarding the ability to expel a 50-ml water-filled balloon placed in the rectum. Normal expulsion time is one minute. It has 80–90% specificity and 97% negative predictive value for identifying dyssynergia. Although it has a sensitivity of only 50%, it is a simple and useful screening procedure to identify constipated patients who do not have dyssynergia¹⁶.

Colonic Transit Study

Slow transit constipation (STC) can coexist in 2/3rd of patients with DD, and it is imperative to differentiate between patients with isolated DD or mixed with STC. Colon transit study is considered abnormal if more than five markers (20%) are present on a plain abdominal film 5 days after ingestion of a Sitzmarker® capsule containing 24 radio-opaque markers¹⁷.

Colonic Transit Scintigraphy

Colonic transit scintigraphy is indicated in patients with suspected colonic motility disorders or more diffuse disorders involving the stomach or small intestine. It quantifies slow colonic transit in patients with constipation and can influence patient management. Two methods have been described: 1. Colon transit of ¹¹¹In DTPA-labeled water consumed in a standard solid-liquid meal for gastric scintigraphy 2. A capsule (containing ¹¹¹In adsorbed on activated charcoal) coated with the pH-sensitive polymer methacrylate that dissolves in the alkaline terminal ileum, releasing the radioisotope into the lumen. The clinical utility of scintigraphic testing has been demonstrated in previous studies. The colonic transit scintigraphy is recommended for assessing colonic transit in patients with constipation or diarrhea but is available in a limited number of centers¹⁸.

Wireless Motility Capsule Test (SmartPill^®)

The Wireless Motility Capsule (WMC) (Smart Pill Corporation, Buffalo, NY), is a wireless pH, temperature and pressure recording capsule. This novel, valuable ambulatory technique of assessing regional (gastric, small bowel, colonic) and whole-gut transit time without radiation offers a standardized method of identifying normal and slow colonic transit^18–20 and recommended as useful by the American Neurogastroenterology & Motility Society. Currently the FDA has approved the SmartPill GI Monitoring System, version 2.0, for the evaluation of colonic transit time in patients with suspected chronic constipation, and for evaluating patients with suspected gastroparesis.

3D Anal Ultrasonography

Three-dimensional endoanal ultrasonography (3D-EAUS) provides excellent anatomical details of the anal sphincter complex, including coronal and segmental sections. It is well-tolerated and inexpensive. The sphincter anatomy can be evaluated spatially, and "damaged" sphincter integrity and volume, as well as fistulous track(s) or potential fluid collections can be assessed²¹.

MR (magnetic resonance) Defecography

MR Defecography (MRD) visualizes the pelvic viscera and supporting soft-tissue structures without radiation but not widely available. It can be performed with a closed or open system. Open MRI acquires images in a sitting position, simulating true defecation. In a closed-configuration MRI system, images are acquired in the supine position²². A recent study demonstrated that Dynamic MRD with an open-configuration and low-field tilting MR system is feasible²³.

Management General and supportive therapies

Medical treatment consists of avoiding constipating medications, increasing fluid and dietary fiber intake, regular exercise, and practicing timed toilet training²⁴. The American College of Gastroenterology (ACG) task force has defined levels of evidence and graded most treatments. Level I evidence was defined: Randomized Control Trials (RCTs) with P<0.05, adequate sampling and appropriate methodology. Level II: RCTs with P<0.05, with inadequate sample size and/or inappropriate methodology. Level III: Non randomized trials with contemporaneous controls. Level IV: Non randomized trials with historical controls. Level V: Case series. Grade A recommendations are supported by two or more level I trials without conflicting evidence from other level I trials. Grade B recommendations are based on evidence from a single level I trial OR recommendations based on evidence from two or more level I trials with conflicting evidence from other level I trials OR supported by evidence from two or more level II trials. Grade C recommendations are based on level III-V evidence²⁵. A fiber intake of 20–25 grams per day is recommended, and if required supplemented with psyllium (grade B recommendation). A recent study had shown that dried plums, 50gm BID, are more effective than equivalent dose of psyllium for mild to moderate constipation²⁶. However, this study was published recently and dried plums were not graded by the ACG task force. Although medications that promote bowel movement such as stool softeners, stimulant laxatives, and osmotic laxatives can be useful in clinical practice, the ACG task force states that there is insufficient evidence for these treatments²⁵. The ACG gave polyethylene glycol (PEG) a grade A. A recent 6 month study reported adequate relief of constipation in 52% of patients treated with PEG compared to 11% treated with placebo²⁷.

Lubiprostone, a chloride channel-2 activator, at a dose of 24ug BID was more effective than placebo in improving stool frequency and symptoms of chronic constipation (CC)²⁵. Prucalopride, a 5-hydroxytryptamine-4 receptor agonist at a dose of 2–4mg QD was also effective in the treatment of CC, and although not FDA approved, it is approved for use in Europe²⁸. Linaclotide, a luminally acting agonist of the guanylate cyclase-C receptor, produces rapid and sustained improvement of bowel symptoms, global relief, and improved quality of life²⁹. It is currently under FDA review for the treatment of irritable bowel syndrome with constipation (IBS-C) and chronic constipation (CC). Thus far, their efficacy in dyssynergic defecation has not been validated.

Biofeedback Therapy

This is the most effective treatment for DD. The main purpose is to restore a normal pattern of defecation using “operant conditioning” techniques³⁰. The primary goals: (i) correct the underlying dyssynergia; and (ii) improve rectal sensory perception. The goals are to improve abdominal push effort, facilitate pelvic floor relaxation, and expel artifical stool. The procedure involves placing a manometric probe into the rectum which in turn provides instant feedback to the patient regarding their performance and how the rectal and anal muscles are behaving. About 10–15 maneuvers are usually attempted in a single session, and the number of sessions and duration of each session are customized. Typically 4–6 sessions, one hour each are performed.

Several randomized controlled trials have demonstrated that biofeedback therapy is superior to sham feedback, standard therapy, or laxatives in the management of patients with DD^31,32. It was not beneficial for patients with isolated slow transit constipation³³. Recently biofeedback has been shown to provide sustained improvement of bowel symptoms and anorectal function for up to one year, whereas standard therapy with laxatives was ineffective³⁴. Also, home biofeedback therapy was as effective as office biofeedback therapy and more cost effective^35,36. Home biofeedback therapy comprised of home training. The patients were instructed to insert a disposable 2 sensor probe into the rectum. The probe is attached to an LCD display box and provides visual input to the subject regarding their performance. The patients practiced at home twice a day for 20 minutes per session. When home biofeedback therapy was compared with the standard treatment of office biofeedback, there was no difference between the two treatments with both treatments showing significant improvement in the number of complete spontaneous bowel movements per week, dyssynergia pattern, balloon expulsion time, and bowel satisfaction score. Currently this treatment is not covered by insurance and could cost up to $400/month which may limit its application. (Table 1).

Table 1.

Summary of the randomized controlled trials of biofeedback therapy for dyssynergic defecation

	Rao et al (35)	Chiarioni et al (32)	Rao et al (86)	Chiarioni et al (34)	Heymen et al (33)
Trial Design	Biofeedback versus standard	Biofeedback versus polyethylene glycol, 14.6 g	Biofeedback versus standard versus sham biofeedback	Biofeedback for slow transit versus dyssynergia	Biofeedback versus diazepam, 5 mg, versus placebo
Subjects and randomization	26 (23 women) 13 Biofeedback 13 standard	104 women 54 biofeedback 55 polyethylene glycol	77 (69 women) 1:1:1 distribution	52 (49 women) 34 dyssynergia 12 slow transit 6 mixed	84 (71 women) 30 biofeedback 30 diazepam 24 placebo
Duration and number of biofeedback sessions	3 months 6,9,12, months reinforcement sessions	3 months and 1 year, 5 weekly, 30-minute training sessions performed by physician investigator	3 months, biweekly, 1 hour, maximum of six sessions over 3 months, performed by biofeedback nurse therapist	Five weekly 30-minute training sessions, performed by physician investigator	Six biweekly, 1-hour sessions
Primary outcomes	Number of complete spontaneous bowel movements (CSBM)	Global improvement of symptoms Worse=0 No improvement=1 Mild=2 Fair=3 Major improvement=4	1. Presence of dyssynergia 2. Balloon expulsion time 3. Number of complete spontaneous bowel movements (CSBM) 4. Global satisfaction	Symptom improvement None=1 Mild=2 Fair=3 Major=4	Global symptom relief
Dyssynergia corrected or symptoms improved	The number of CSBMs per week increased significantly (P<0.001) in the biofeedback group	79.6% reported major improvement at 6 and 12 months, 81.5% reported major improvement at 24 months	Dyssynergia corrected at 3 months in 79% with biofeedback versus 4% sham and 6% in standard group; CSBM=biofeedback group versus sham or standard, p<0.05	71% with dyssynergia and 8% with slow transit alone reported fair improvement in symptoms	70% improved with biofeedback compared with 38% with placebo and 30% with diazepam
Conclusions	Biofeedback provided sustained improvement compared to standard therapy	Biofeedback was superior to laxatives	Biofeedback was superior to sham feedback and standard therapy	Biofeedback benefits dyssynergia and not slow transit constipation	Biofeedback is superior to placebo and diazepam

Rectal Prolapse

Rectal prolapse is defined as an abnormal protrusion of all layers of the rectal wall through the anus. The incidence is 2.5/100,000, with the highest incidence among elderly women. In younger people, the gender ratio is equal³⁷.

The primary mechanism is excessive straining, that over many years gradually weakens the pelvic floor and its support structures. The repeated injury to the pudendal nerve and other nerves weakens the IAS and EAS and the puborectalis. The lax anal sphincters offer very little counter-acting resistive force during defecation, thereby leading to an abnormal protrusion of the rectal wall through the anus. Other causes for prolapse include pudendal neuropathy from either aging or obstetric injury.

Most patients present with anal protrusion and/or passage of blood, or symptoms of obstructed defecation or fecal incontinence³⁸. Pre-existing dysmotility, DD, or intussusception also predispose. Anal inspection may reveal normal anal area but when the patient bears down the prolapsed rectum is visible, often edematous and sometimes with a friable and ulcerated mucosa. Rectal prolapse is graded into four types: grade 1=up to anal verge; grade 2=prolapse outside the anus but reduces spontaneously; grade 3=prolapses outside the anus but can be manually reduced; and grade 4=prolapse cannot be reduced manually.

Diagnosis

The diagnosis is made through careful perineal examination and during attempted defecation. A patulous anus with full thickness rectal protrusion is usually diagnostic. If not seen at bedside, a Valsalva maneuver on commode should bring on the prolapse; a prone jackknife position is not helpful. Endoscopic evaluation to identify other causes associated with rectal prolapse may be useful. Defecography usually demonstrates the prolapse, and may reveal an obtuse anorectal angle. MRD may reveal other anatomical defects that can aid in assessment of surgical intervention. 3D-EAUS may show asymmetry and thickening of the IAS and submucosa. Demonstration of anal sphincter defect is useful when considering sphincter reconstruction³⁹. Anorectal manometry may reveal sphincter weakness especially in patients with coexisting fecal incontinence. Rectal sensation and compliance may be either normal or impaired⁴⁰.

Management

Grade 1–2 prolapse that is asymptomatic does not require surgery, and could be managed with high-fiber diet and/or laxatives, followed by biofeedback therapy to correct underlying dyssynergia. However, symptomatic grade 3–4 prolapse requires surgery. Both abdominal and perineal approaches are available. The abdominal approach allows the surgeon to deal with factors that are associated with rectal prolapse including a deep cul-de-sac of the pouch of Douglas, lack of sacral fixation, and redundancy of the sigmoid colon⁴¹. The method used to mobilize the rectum is controversial due to evidence suggesting that this may cause or worsen constipation in 1/3rd of patients while decreasing the risk of prolapse recurrence. Sacral fixation of the rectum is accomplished by either posterior suture or mesh rectopexy. Resection of sigmoid colon is preferably performed in patients with significant redundancy, but is avoided in patients with the combination of diarrhea and/or incontinence as these symptoms may worsen with resection⁴².

Perineal repairs are currently the most common surgical treatment for rectal prolapse in the US⁴³. The perineal approach has a lower perioperative morbidity and higher recurrence rate and less satisfactory functional results⁴⁴. In general, elderly patients, those with significant medical comorbidities, or those with contraindications for abdominal surgery are often the best candidates. Most commonly a perineal proctosigmoidectomy (Altemeir procedure) is performed⁴⁵. This may be combined with transperineal levatoroplasty which may help to reduce the risk of recurrence⁴⁶. Recent studies have shown that robotic colorectal resection is a safe and feasible option; however, more studies are required⁴⁷.

Recurrence rates for transabdominal rectopexy are low (0–8%); however, after posterior rectopexy 50% of patients complain of severe constipation⁴⁸. Perineal procedures have a recurrence rate of 5–21% with similar incidence of constipation.

Rectocele

Rectocele is an abnormal sac-like protrusion of the rectal wall either towards the vagina (anterior) and rarely towards the sacrum (posterior) that often becomes apparent during defecation (Figure 3A, 3B). It is common in adult women (20%), majority are small (<2 cm), asymptomatic, and require no treatment^49,50.

Figure 3.

A. Normal MR Defecogram showing normal sized rectum filled with contrast and adjacent pelvic muscular and bony structures. Reproduced, with permission, from Roos J, Weishaput D, Wildermuth S, Willmann J, Marincek B, Hilfiker P, Experience of 4 Years with Open MR Defecography: Pictorial Review of Anorectal Anatomy and Disease, Radiographics, 2002, 22, 819.

B. Abnormal MR Defecogram during an attempted defecation showing a large anterior rectocele (>4 cm). Reproduced, with permission, from Roos J, Weishaput D, Wildermuth S, Willmann J, Marincek B, Hilfiker P, Experience of 4 Years with Open MR Defecography: Pictorial Review of Anorectal Anatomy and Disease, Radiographics, 2002, 22, 825.

Rectocele is believed to be caused by weakness of the rectovaginal septum and/or pelvic floor; however, the exact etiology is not known. Obstetric injury and multiple vaginal deliveries have been proposed as precipitating factors. However, rectocele is also seen in nulliparous women^37,51. There are no specific anorectal physiological findings for a rectocele, a previous study had reported that dyssynergic pattern of defecation was seen in 60% of patients with rectocele when compared to 24% without a rectocele⁵². However, a recent study showed similar prevalence⁵³. Rectocele can be a cause or consequence of CC with excessive straining, and may be associated with DD or rectal mucosal intussusception, or excessive perineal descent. Whether it is a cause or an effect of these changes is unclear^3,52. Excessive straining or childbirth may weaken the vaginal septum. Consequently, during defecation a pressure gradient is created between the higher intrarectal pressure and lower vaginal pressure producing a rectocele. Rectocele is usually asymptomatic, and is diagnosed by examination or defecography. Patients may report symptoms such as a feeling of incomplete evacuation, prolonged straining, or vaginal splinting. Some report a vaginal or perineal bulge and others describe a sensation of blockage or inability to evacuate³⁷. Patients may complain of dyspareunia, anorectal/vaginal pain, fecal soiling, and urologic symptoms⁵⁴.

Diagnosis

DRE may reveal an anterior out pouching of the rectal wall, particularly during straining. Bimanual rectal and vaginal examination can further help to confirm or facilitate diagnosis. A posterior rectocele is difficult to detect clinically.

Defecography is considered the gold standard for diagnosis of anterior or posterior rectocele, measure its size, and quantify stool retention. It also provides information regarding coexisting conditions such as rectal mucosal intussusception or excessive perineal descent⁵⁵. Clinical correlation is important before labeling a rectocele as clinically significant. Rectoceles >3 cm and those with retention of barium or stool are considered to be clinically significant. Although widely used for identification and staging of rectoceles, defecography cannot predict the outcome of rectocele repair (REF). Anal sphincter pressures, rectal sensation, and rectal compliance are usually normal but one study found dyssynergia in about 50% of patients with rectocele <2.5 cm⁵⁶.

MRI provides good visualization of the rectocele, and dynamic MRI can correlate with pelvic floor movements. It is recommended that real-time continuous imaging with a dynamic true fast imaging with steady-state precession sequence should be included in MR protocols to evaluate pelvic floor dysfunction in addition to dynamic multiplanar sequences⁵⁷. A recent study showed that images during the defecation phase can identify abnormal bladder, vaginal, and rectal descent and previously undetected rectoceles that were ≥2 cm⁵⁸.

Management

The first approach is to treat any underlying defecation disorder. Fiber supplements, laxatives, timed-toilet training, and behavioral approaches can be effective but has not been systematically evaluated. If symptoms persist and DD is identified, biofeedback may help. It is important to identify and treat co-existing psychological disorders and other organic disorders (urogynecological)^59,60. Surgical treatments carry a high risk of recurrence for both rectocele and rectal mucosal intussusception. However, surgery is appropriate for patients with large rectocele (>3 or 4 cm) or those with coexisting vaginal prolapse, but after failure of medical therapy. In these patients, rectocele repair improves anorectal function by improving rectal sensitivity⁶¹.

Surgical repair of a rectocele must be tailored to each patients needs, keeping in mind that uterovaginal and rectal prolapse may co-exist, and generally a transperineal repair is superior to transanal repair for both structural and functional outcome⁶². In patients with both rectocele and DD, the transanal approach is ideal, although it may compromise anal sphincter pressures. The stapled transanal rectal resection approach uses sequential deployments of a gastrointestinal stapling device to resect the redundant anterior and posterior rectal walls, thereby restoring normal rectal anatomy and reducing rectal volume. However, a recent long-term study demonstrated rapid deterioration in outcomes after 18 months⁶³.

Descending perineum syndrome

Descending perineum syndrome (DPS) is characterized by ballooning and excessive descent of the perineum, often several centimeters below the bony outlet of the pelvis, during straining⁶⁴ (Figure 4).

Figure 4.

MR defecogram study showing excessive (>4 cm) descent of the perineum during straining, typical of the Descending Perineum Syndrome (White line= Pubococcygeal line). Reproduced, with permission, from Roos J, Weishaput D, Wildermuth S, Willmann J, Marincek B, Hilfiker P, Experience of 4 Years with Open MR Defecography: Pictorial Review of Anorectal Anatomy and Disease, Radiographics, 2002, 22, 828.

Typically, patients present with a long history of painful defecation, excessive straining, and sense of incomplete evacuation or fecal incontinence⁶⁵. One study showed a link between DPS, fecal incontinence, and abdominal hysterectomy⁶⁶.

DPS can be diagnosed on physical examination, or defecography. The most common abnormality is >4 cm perineal descent at rest or ≥3 cm perineal descent during a maximal push effort⁶⁷. A perineometer, which measures the strength of voluntary contractions of the pelvic floor muscles, may be useful⁶⁸.

Dynamic MR imaging demonstrates simple or complex organ descent in all pelvic compartments and may become standard preoperative evaluation for pelvic floor abnormalities. The MR images facilitate planning of surgery and can increase rate of successful outcome, but is expensive and not widely available⁶⁹.

Management

Treatment consists of mainly correcting the excessive straining, use of an artificial device-defecom - a polycarbonate plate with two separate holes for passing urine and stool and a built in hump which supports the perineum when sitting on a commode. The defecom together with biofeedback therapy may improve symptoms in ~50%⁷⁰. Pelvic floor retraining may also be useful but there is no information and the extent of perineal descent appears to be a useful predictor of response to retraining. The defecom and a similar device “Colorec”, are unavailable in the USA and not FDA approved.

Until recently, there was no surgical option for isolated DPS. However, recently a retrospective case series of nine women who underwent isolated retro-anal levator plate myorrhaphy for symptomatic DPS⁷¹. The mean reduction of perineal descent was 1.08 cm (0–1.5) reported after 9 months. There was improvement in stress urinary incontinence (100%), frequency, nocturia, urgency (66%), dysuria (75%), fecal incontinence (100%), dyschezia (87%), dyspareunia (80%), cystocele and rectocele (75%). A prospective controlled study is needed to validate this result.

Solitary rectal ulcer syndrome

Solitary rectal ulcer syndrome (SRUS) is characterized by erythema and single/few ulcers. Its etiology remains obscure but is often associated with evacuation disorders. The annual incidence of SRUS is 1–3.6/100,000; 80% of patients are less than 50 years of age⁷² with slightly higher prevalence in females. Rectal intussusception is often present and evacuation is delayed^73,74. Ulceration is thought to occur during repeated forceful straining against an immobile pelvic floor or DD together with trauma from digital manipulations and ischemic necrosis of the prolapsing rectal mucosa⁷⁵. Patients present with rectal bleeding and/or pain, mucus discharge, straining and tenesmus and a feeling of incomplete evacuation. Majority use digital maneuvers but rarely admit. About 55% present with constipation, 20–40% with diarrhea, and 25% are asymptomatic, and 25% are misdiagnosed or treated as inflammatory bowel disease. In some patients, an underlying psychologic disorder, such as obsessive-compulsive disorder may be present⁷⁴.

Diagnosis

Sigmoidoscopy may reveal a small, shallow ulcer with a white slough or hyperemic mucosa on the anterior wall of the rectum (Figure 5). The lesions can be multiple (30%), ulcerated (57%), polypoid (25%) or with patches of hyperemic mucosa (18%). SRUS is usually found on the anterior or anterolateral wall of the rectum, over a rectal fold, about 5–10cm from anus⁷⁶. Histologically, the mucosa appears elongated with distorted glands at the base, with an edematous fibroblast-rich lamina propria and thickened inner circular muscular layer⁷⁷. When the glands migrate down to the submucosa, bleeding may occur. Pathognomonic features in SRUS include: decussation of the two muscularis layers, nodular induration of the inner layer, and grouping of outer longitudinal layers into bundles⁷⁸. Biopsy is needed to differentiate SRUS from ulcers due to other etiologies (NSAIDs, malignancy, endometriosis)^79,80. Defecography may show other abnormalities such as rectal mucosal intussusception in 45–80% of subjects. Barium enema is unreliable⁸¹. Anorectal manometry does not help in establishing the diagnosis or predicting therapeutic response; however, it may reveal a number of physiological abnormalities such as dyssynergia in 80% of patients or a hypersensitive rectum, and prolonged BET⁸². Ultrasonography may show marked thickening of the IAS, submucosa, and EAS, as well as rectal wall and muscularis propria⁷⁸.

Figure 5.

Solitary rectal ulcer syndrome. Endoscope view of an ulcer (white area towards upper right) in a patient’s rectum. Photo Researchers Picture Number: C013/0462. Credit: Gastrolab/Photo Researchers, Inc. License: Rights Managed.

Management

Behavioral therapy remains the mainstay of treatment and includes reducing excessive straining, spending less than 5 minutes during evacuation, and discontinuing the use of digital maneuvers. These recommendations, together with biofeedback therapy improved symptoms in 67% of patients with sigmoidoscopic improvement in 30%⁷⁶. A high-fiber diet showed a variable response rate of 19–70%, suggesting that although diet helps by itself, it is insufficient. Local treatment with topical steroids and sulphasalazine is generally ineffective. Although there is limited data, sucralfate enemas and topical human fibrin sealant have been tried⁸³. A recent study suggests that Argon plasma coagulation (APC) may be useful in controlling bleeding and improving healing of ulcers, but controlled studies are lacking⁸⁴.

Biofeedback therapy appears to be effective, although RCTs are scarce. One study showed that 75% (12/16) of patients had symptomatic improvement with biofeedback therapy and 31% (5/16) had ulcer resolution on sigmoidoscopy⁸⁵. Mucosal flow improved in patients who felt subjectively better after biofeedback. Another prospective study of 11 patients with refractory SRUS showed that biofeedback therapy improved straining effort and stool frequency, digital maneuvers were discontinued in 45% and bleeding ceased in 56%. Ulcer healing was reported in 10 patients: 4 had complete healing, 2 had >50%, and 4 had <50%⁷⁵.

Rectopexy with or without anterior resection should be performed in highly selected cases. Outcomes of surgery are often disappointing, because of either persistent symptoms, postoperative bleeding or sexual dysfunction^86,87. (Figure 6).

Figure 6.

Algorithm for investigation and treatment of Solitary Rectal Ulcer syndrome (SRUS)

Conclusions

Pelvic floor disorders that cause difficulty with defecation are very common and predominantly affect women. A gastroenterologist or colorectal surgeon is best suited to evaluate and manage these problems but there is lack of experience and working knowledge of these conditions. Physiologic tests such as ARM, balloon expulsion test, and imaging such as defecography and MRI play a key role in objective diagnosis. Biofeedback therapy is an established treatment not only for patients with DD but also for others such as SRUS. Dyssynergia may also co-exist with other structural disorders such as SRUS or rectocele. Hence, before considering surgery, biofeedback therapy should be considered. Correcting the underlying pathophysiological dysfunction offers patients a better control of their symptoms. (Figure 7).

Figure 7.

Suggested algorithm for evaluation and management of common pelvic floor disorders

Several surgical approaches including open, laparoscopic, trans-abdominal approach, stapled transanal rectal resection, and robotic colon and rectal resections have been advocated, and may prove useful in selected cases, but lack randomized controlled trials and rigorous outcome measures.