Overview

Definition:
-Pelvic floor dyssynergia (PFD), also known as anismus or functional defecatory disorder, is characterized by discoordination of the pelvic floor muscles during attempted defecation
-This involves paradoxical contraction of the external anal sphincter and/or puborectalis muscle, along with inadequate relaxation of these muscles, leading to impaired expulsion of stool
-It is a subtype of chronic constipation.
Epidemiology:
-PFD is a common cause of chronic constipation, affecting a significant proportion of patients presenting with defecatory dysfunction
-Prevalence estimates vary, but it is found in up to 50% of patients referred to tertiary defecation disorders clinics
-It can affect both men and women, with some studies suggesting a slightly higher prevalence in women.
Clinical Significance:
-Understanding the surgical interface of PFD is crucial for surgeons dealing with chronic constipation and defecatory dysfunction
-Inadequate diagnosis and management can lead to persistent symptoms, reduced quality of life, and psychological distress
-Surgical interventions are typically reserved for refractory cases after conservative management has failed, and require careful patient selection and procedural execution.

Clinical Presentation

Symptoms:
-Feeling of incomplete evacuation
-Straining during defecation
-Need for manual maneuvers (e.g., digital evacuation, perineal pressure) to defecate
-Frequent bowel movements with passage of small amounts of hard stool
-Bloating and abdominal discomfort
-Rectal pain or pressure
-Sensation of anal blockage.
Signs:
-Physical examination may reveal an hypertrophied or poorly relaxed external anal sphincter on digital rectal examination (DRE)
-Rectal prolapse or intussusception may be present
-Paradoxical contraction of the puborectalis muscle may be elicited during attempted defecation maneuvers.
Diagnostic Criteria:
-Diagnosis is primarily based on clinical symptoms and confirmed by anorectal manometry, specifically demonstrating paradoxical contraction of the puborectalis or external anal sphincter during attempted defecation, or inadequate relaxation
-Rome IV criteria for Functional Constipation or Obstructed Defecation Syndrome are often met.

Diagnostic Approach

History Taking:
-Detailed history of bowel habits, including frequency, consistency, straining, sensation of incomplete evacuation, and need for manual maneuvers
-Assess for red flags such as rectal bleeding, unintentional weight loss, family history of colorectal cancer, or change in stool caliber suggesting obstruction
-Evaluate prior treatments and response.
Physical Examination:
-General abdominal examination
-Digital rectal examination (DRE) to assess sphincter tone, presence of stool, rectal masses, and assess for paradoxical contraction during attempted defecation
-Perineal inspection for prolapse or scarring
-Assessment for pelvic organ prolapse in women.
Investigations:
-Anorectal manometry: Gold standard for diagnosing PFD, demonstrating inadequate relaxation or paradoxical contraction of pelvic floor muscles during defecation attempt
-Balloon expulsion test: Assesses ability to expel a balloon, which may be impaired in PFD
-Defecography or dynamic MRI: Can identify rectal intussusception, rectocele, or perineal descent, often co-existing with PFD
-Colon transit study: To assess overall colonic motility and rule out slow transit constipation.
Differential Diagnosis:
-Other causes of obstructed defecation: Rectal prolapse, rectocele, intussusception, anal stricture, fecal impaction
-Irritable bowel syndrome with constipation (IBS-C)
-Pudendal neuralgia
-Hirschsprung's disease (in younger patients)
-Slow transit constipation.

Management

Initial Management:
-Biofeedback therapy: First-line treatment for PFD, aims to retrain pelvic floor muscle coordination by providing visual or auditory feedback
-Dietary modifications: High-fiber diet and adequate fluid intake
-Bowel training program: Regular toileting and establishing a defecation routine.
Medical Management:
-Laxatives: Osmotic laxatives (e.g., polyethylene glycol) or stimulant laxatives may be used cautiously to facilitate bowel movements, but are not curative for PFD itself
-Prokinetics are generally not effective for PFD.
Surgical Management:
-Surgical intervention is reserved for severe, refractory cases of PFD unresponsive to comprehensive conservative management, especially when co-existing structural abnormalities are identified
-Indications include severe symptoms, significant structural defects, and failure of biofeedback and medical therapy
-Procedures may include rectocele repair, rectopexy (for rectal prolapse), STARR (stapled transanal rectal resection) procedure for obstructed defecation, or sacral neuromodulation
-The surgical approach is individualized based on the specific anatomical derangement identified on defecography/MRI and manometry findings.
Supportive Care:
-Psychological support: Addressing anxiety and depression associated with chronic constipation
-Pelvic floor physiotherapy beyond biofeedback for core muscle strengthening and relaxation techniques.

Complications

Early Complications:
-Postoperative pain
-Bleeding
-Infection
-Urinary retention
-Fecal incontinence (temporary or persistent).
Late Complications:
-Recurrence of symptoms
-Anal stricture
-Persistent fecal incontinence
-Development of rectovaginal or rectourethral fistula (rare)
-Failure of surgery.
Prevention Strategies:
-Careful patient selection for surgery
-Meticulous surgical technique
-Appropriate postoperative care and rehabilitation
-Avoiding unnecessary surgical intervention.

Prognosis

Factors Affecting Prognosis:
-Severity of PFD
-Presence of co-existing structural abnormalities
-Patient adherence to biofeedback and lifestyle modifications
-Successful correction of anatomical defects
-Surgeon's experience.
Outcomes:
-Biofeedback therapy has a high success rate for PFD, often leading to significant symptom improvement
-Surgical outcomes are variable and depend on the procedure performed and the underlying pathology
-Success rates for STARR procedures and sacral neuromodulation vary but can provide relief in carefully selected patients
-Long-term outcomes require ongoing management and lifestyle adjustments.
Follow Up:
-Regular follow-up with a specialist is essential, particularly after surgical intervention
-This includes monitoring bowel function, assessing for recurrence of symptoms, and managing any late complications
-Continued participation in physiotherapy or bowel training programs may be beneficial.

Key Points

Exam Focus:
-PFD is a motility disorder requiring diagnosis via manometry
-Biofeedback is the cornerstone of non-surgical management
-Surgery is reserved for refractory cases with identifiable structural defects, often involving procedures like STARR or rectopexy.
Clinical Pearls:
-Always consider PFD in patients with chronic constipation and straining despite adequate fiber and fluid intake
-Digital rectal examination during attempted defecation can be highly informative
-Co-existing conditions like rectocele or prolapse often need to be addressed surgically alongside PFD management.
Common Mistakes:
-Over-reliance on laxatives without addressing the underlying coordination issue
-Performing surgery without adequate pre-operative workup and failed conservative trials
-Inadequate biofeedback training leading to poor patient compliance
-Misinterpreting manometry findings or overlooking structural abnormalities.