What treatments can restore sensation in a lax or overstretched puborectalis muscle in men?

Restoring Puborectalis Sensation in Men

Pelvic floor biofeedback therapy with sensory retraining is the evidence-based first-line treatment for restoring sensation in a lax or overstretched puborectalis muscle, achieving success rates exceeding 70% when properly implemented. 1, 2

Understanding the Problem

The puborectalis muscle is part of the levator ani complex and plays a critical role in both continence and defecation. When this muscle becomes lax or overstretched—whether from chronic straining, neurologic injury, or other causes—patients often experience:

• Loss of rectal sensory awareness (rectal hyposensitivity), making it difficult to detect the urge to defecate 1
• Impaired coordination between abdominal push effort and pelvic floor relaxation 1
• Symptoms of fecal incontinence or paradoxical constipation depending on the specific dysfunction 3

The key insight is that sensation loss is often a learned dysfunction rather than permanent nerve damage, meaning the brain has lost awareness of pelvic floor activity that can be retrained through structured therapy. 1

Diagnostic Confirmation Before Treatment

Do not proceed with empiric treatment—anorectal manometry (ARM) with sensory testing is essential to confirm the diagnosis and guide therapy. 1, 2

ARM will identify:

• Elevated sensory thresholds (first sensation >60 mL, urge to defecate >120 mL, maximum tolerable volume >200 mL) confirming rectal hyposensitivity 1
• Baseline anal resting tone to rule out concurrent sphincter hypertonicity or weakness 1
• Dyssynergic patterns during simulated defecation that may coexist with sensory deficits 1

Document at least two abnormal sensory parameters to ensure reliable diagnosis, as single measurements can be subjective. 1

First-Line Treatment: Biofeedback with Sensory Retraining

Why Biofeedback Works

Biofeedback therapy directly addresses the underlying sensory-motor disconnect through three mechanisms:

1. Sensory adaptation training uses serial balloon inflations during therapy sessions to retrain rectal sensory perception, enabling patients to detect progressively smaller volumes of rectal distension 1
2. Operant conditioning with real-time visual feedback converts unconscious pelvic floor muscle activity into observable data that patients can consciously modify 1
3. Rectal sensorimotor coordination training improves the integration of sensory awareness with motor response 1

Treatment Protocol (8-Week Course)

Initiate structured biofeedback as first-line therapy rather than observation or empiric medications. 1

The protocol consists of:

• 5-6 weekly sessions (30-60 minutes each) using anorectal probes with rectal balloon simulation 1
• Real-time visual display showing anal sphincter pressure and abdominal push effort, enabling patients to see pelvic floor activity and learn coordination 1
• Progressive sensory adaptation exercises: Patients report sensation thresholds at each balloon distension step, gradually training awareness of smaller volumes 1
• Daily home relaxation exercises (not strengthening exercises) with bowel movement diaries 1
• Proper toilet posture (foot support, hip abduction) to reduce inadvertent abdominal muscle activation 1

Expected Outcomes

• Success rates of 70-80% are achievable in appropriately selected patients with rectal sensory dysfunction 1
• Patients with less severe baseline hyposensitivity (lower sensory thresholds) respond more favorably 1
• Depression is an independent predictor of poor efficacy—screen for and treat mood disorders concurrently 1
• Therapy is completely free of morbidity; only rare, transient anal discomfort has been reported 1

Critical Implementation Requirements

Most pelvic floor physical therapists lack the specialized equipment and training needed for effective sensory retraining biofeedback. 1

Refer patients to:

• Gastroenterology or specialized pelvic floor centers that provide ARM with sensory testing 1
• Clinicians trained in anorectal physiology who use anorectal probes with rectal balloon simulation (not generic pelvic floor strengthening programs) 1
• Programs that provide real-time visual feedback of anal sphincter pressure during simulated defecation 1

Generic pelvic floor physical therapy focused on Kegel exercises (strengthening) is inappropriate and potentially harmful for puborectalis laxity with sensory deficits, as it does not address the sensory retraining component. 1, 4

Adjunctive Measures During Therapy

• Aggressive constipation management (fiber supplementation to 25-30 g/day, polyethylene glycol 15-30 g/day) should continue throughout biofeedback to prevent stool withholding that reinforces dysfunction 1
• Scheduled toileting after meals to synergize with the gastrocolonic response 2
• Avoid medications that worsen constipation (opioids, anticholinergics, calcium channel blockers) if feasible 2, 1

Second-Line Option: Sacral Nerve Stimulation

Consider sacral nerve stimulation (SNS) only after completing an adequate 3-month biofeedback program without clinically meaningful improvement. 1

Small case series suggest SNS may improve rectal sensation in patients with rectal hyposensitivity, but:

• Evidence is limited to retrospective analyses with modest functional benefit 1
• SNS is not a first-line therapy and should not replace biofeedback 1
• The mechanism appears to involve neuromodulation of sacral sensory pathways, but data for functional bowel improvement remain insufficient 1

Common Pitfalls to Avoid

1. Referring to generic pelvic floor PT without ARM confirmation: This leads to inappropriate strengthening exercises when relaxation training is needed 1
2. Confusing sensory retraining with standard biofeedback for fecal incontinence: The protocols differ fundamentally—incontinence therapy focuses on sphincter strengthening, while sensory retraining focuses on awareness and coordination 1, 3
3. Progressing to invasive treatments without adequate biofeedback trial: Conservative measures alone improve only 25% of patients, but proper biofeedback achieves 70-80% success 1
4. Failing to screen for depression: Untreated mood disorders independently predict biofeedback failure 1
5. Expecting immediate results: Sensory retraining requires 8+ weeks of structured therapy with home practice 1

When Biofeedback Fails

If symptoms persist after completing a full biofeedback course with documented adherence:

• Repeat ARM to reassess sensory thresholds and identify any change 1
• Consider SNS as described above 1
• Evaluate for alternative diagnoses such as neurogenic bowel dysfunction, spinal cord pathology, or structural abnormalities requiring surgical correction 2