What is the stepwise day‑to‑day treatment for anismus (paradoxical pelvic‑floor contraction during attempted defecation)?

Treatment of Anismus (Dyssynergic Defecation) in Daily Life

Pelvic floor retraining by biofeedback therapy is the definitive treatment for anismus, achieving success rates exceeding 70% when properly implemented, and should be initiated after confirming the diagnosis with anorectal manometry rather than continuing laxatives indefinitely. 1

Step 1: Initial Conservative Trial (2-4 Weeks)

Before pursuing diagnostic testing, attempt a brief conservative trial:

• Discontinue constipating medications including opioids, anticholinergics, and cyclizine 2
• Gradually increase fiber intake to 25-30 g/day through dietary sources and supplements (e.g., psyllium 15 g daily) 2
• Add polyethylene glycol (15-30 g/day) or milk of magnesia as an inexpensive osmotic agent (approximately $1/day) 2
• Consider stimulant laxatives (bisacodyl or glycerin suppositories) administered 30 minutes after meals to synergize with the gastrocolonic response 2
• Warm sitz baths (15-20 minutes, 2-3 times daily) provide temporary symptomatic relief but do not address the underlying dyssynergia 2

Critical caveat: Conservative measures alone improve only approximately 25% of patients with pelvic floor dysfunction 2, 3. Do not continue escalating laxatives indefinitely—this violates guideline recommendations and delays definitive treatment. 3, 4

Step 2: Diagnostic Confirmation with Anorectal Testing

When conservative measures fail after 2-4 weeks, perform anorectal manometry to confirm dyssynergic defecation before initiating biofeedback. 1, 2

Key diagnostic findings include:

• Paradoxical anal contraction (increased anal pressure) during attempted defecation 3
• Hypertonic resting pressure >70 mmHg 2, 3
• Impaired balloon expulsion (failure to expel within 60 seconds) 5, 6
• Sensory abnormalities (rectal hyposensitivity or hypersensitivity) may coexist 2

Important pitfall: Simple proctographic criteria overdiagnose anismus and underdiagnose rectal prolapse. 6 Failure to empty barium paste after 30 seconds on defecography is used as a surrogate for simultaneous EMG/proctography but has limitations. 6

Step 3: Definitive Treatment with Biofeedback Therapy

Biofeedback is the gold-standard, first-line therapy with 70-80% success rates when delivered correctly. 1, 2, 3, 4

Essential Components of Effective Biofeedback:

Protocol structure:

• 5-6 weekly sessions, each 30-60 minutes 2, 3
• Anorectal probe with rectal balloon to simulate defecation 2, 3
• Real-time visual feedback displaying anal sphincter pressure decreasing as abdominal push effort increases 2, 3
• Immediate reinforcement when patients successfully relax ("you just relaxed—see the pressure drop") 2, 3

Home program:

• Daily pelvic floor relaxation exercises (not strengthening exercises—Kegel exercises are contraindicated for hypertonicity) 2
• Proper toilet posture with foot support and hip abduction to reduce inadvertent abdominal muscle activation 2
• Continue aggressive constipation management throughout therapy to prevent stool withholding 2

Critical Implementation Requirements:

Most pelvic floor physical therapists lack the specialized equipment and training for dyssynergic defecation. 2 They are typically equipped for fecal incontinence biofeedback (strengthening exercises) but insufficiently prepared for anismus, which requires simultaneous real-time visual feedback of abdominal straining and anal sphincter relaxation. 2

Seek gastroenterologist-supervised programs that use anorectal manometry probes with visual monitoring capability. 2, 4 The 40% of providers who do not perform biofeedback cite institutional barriers rather than efficacy concerns. 2

Predictors of Success and Failure:

Positive predictors:

• Motivated patients willing to complete the full course 5
• Shorter symptom duration before treatment (mean 33 months in responders vs. 81 months in non-responders, P<0.01) 7
• Isolated obstructed defecation symptoms (OR=7.8, P=0.008) 6

Negative predictors:

• Depression is an independent predictor of poor efficacy; screen and treat mood disorders concurrently 2
• Long-standing symptoms (>5 years) correlate with treatment failure 7

Reassuring finding: Age, gender, previous anorectal surgery, baseline manometry pressures, and associated anatomic abnormalities (rectoceles, perineal descent) do not predict outcome. 8, 7 Success is not related to reversal of paradoxical contraction on post-treatment manometry. 8

Safety Profile:

Biofeedback is completely free of morbidity and safe for long-term use. 1, 2 Only rare minor adverse events such as transient anal discomfort have been reported. 2

Step 4: Adjunctive Pharmacologic Options During Biofeedback

If constipation symptoms persist despite biofeedback progress:

• Topical calcium-channel blockers (0.3% nifedipine or 2% diltiazem ointment twice daily for 6 weeks) reduce sphincter tone with healing rates of 65-95% 2
• Continue polyethylene glycol and fiber supplementation throughout therapy 2

Do not use nitrate preparations—calcium-channel blockers outperform them. 2

Step 5: Management of Refractory Cases After Adequate Biofeedback Trial

Before declaring biofeedback "failed," verify the patient completed at least 6 instrumented sessions with proper equipment and trained providers. 3 Inadequate therapist training is the most common reason for treatment failure. 2

If Proper Biofeedback Fails:

First, perform examination under anesthesia (EUA) to exclude misdiagnosed rectal prolapse ("pseudoanismus"). 6 In one study, 97% of biofeedback non-responders had significant abnormalities at EUA, with 94% having grade 3-5 rectal prolapse. 6 Excluding these alternative diagnoses revised the response rate to 96%. 6

Second-line options (limited evidence):

• Botulinum toxin injection into the puborectalis muscle (10 units to each side or 20 units posteriorly) achieves manometric relaxation in 75% but symptom improvement in only 37.5% after first injection 9. When rectal prolapse is properly excluded, response rates approach 96%. 6 Overall satisfaction is 58.3%, justifying its use only after adequate biofeedback. 9

• Sacral nerve stimulation may improve rectal sensation in select patients with rectal hyposensitivity, but robust evidence for functional improvement in defecatory disorders is lacking. 2, 3 Cost averages $35,818 versus $796 for a 3-month biofeedback course. 3

Third-line surgical options (for truly refractory cases):

• Venting ileostomy or colostomy (if colonic transit is normal) 1
• Do not perform manual anal dilatation—it carries a 30% temporary incontinence risk and 10% permanent incontinence risk 2

Based on available evidence, botulinum toxin injection or stapled transanal resection cannot be recommended outside of clinical trials for primary treatment. 1

Key Algorithmic Summary:

1. Week 0-4: Conservative trial (fiber, polyethylene glycol, discontinue constipating medications)
2. Week 4: If no improvement → anorectal manometry to confirm dyssynergia
3. Week 5-11: Biofeedback therapy (6 weekly sessions with proper equipment)
4. Week 12+: If adequate response → continue home relaxation program; if inadequate response → EUA to exclude rectal prolapse → consider botulinum toxin or sacral nerve stimulation

The most common pitfall is skipping biofeedback and proceeding directly to invasive interventions—this violates Level A guideline recommendations. 3, 4