What is the treatment for anismus?

Treatment of Anismus

Biofeedback therapy is the first-line treatment for anismus, with combination therapy of acupoint thread embedding plus biofeedback showing superior short-term outcomes, though surgical intervention with partial division of puborectalis muscle combined with lateral internal sphincterotomy should be considered for patients who fail conservative management after 3-6 months. 1, 2, 3

First-Line Conservative Management

Biofeedback Therapy (BFT)

• Biofeedback is the established first-line treatment for anismus, a defecation disorder characterized by paradoxical contraction or failure to relax the puborectalis muscle during attempted defecation 1, 4
• Standard biofeedback achieves clinical improvement in approximately 50% of patients at 1 month, though this drops to only 30% at 1 year 2
• Patients with symptom duration less than 3 years respond significantly better to biofeedback than those with longer symptom duration (33 ± 34 months vs 81 ± 61 months for non-responders, p < 0.01) 4
• The presence of associated pelvirectal disorders (rectocele, rectal prolapse, abnormal perineal descent) does not predict biofeedback failure, so extensive pre-treatment imaging is not mandatory 4

Enhanced Biofeedback Approaches

• Psycho-echo-biofeedback combining guided imagery, relaxation techniques, and ultrasound-assisted biofeedback allows all patients to achieve physiological puborectalis relaxation during the treatment session 5
• This approach is particularly valuable for patients with concurrent anxiety or depression 5
• Previous anorectal surgery is a negative predictor of biofeedback success and should prompt earlier consideration of alternative treatments 5

Combination Therapy with Acupoint Thread Embedding

• The combination of acupoint thread embedding (ATE) plus biofeedback demonstrates significantly superior outcomes compared to either therapy alone, with an 85% total effectiveness rate versus 68.89% for biofeedback alone (p = 0.03) 1
• At 3-month post-treatment, combination therapy produces significantly lower constipation scores, traditional Chinese medicine syndrome scores, and quality of life impairment compared to biofeedback monotherapy 1
• Benefits persist at 3-month follow-up but return to baseline by 6 months, indicating need for maintenance therapy 1

Second-Line Pharmacologic Treatment

Botulinum Toxin Type A Injection

• Botulinum toxin injection into the puborectalis muscle achieves 75% clinical improvement at 1 month but only 35% at 1 year, making it effective for temporary relief but not durable long-term treatment 2
• This approach is appropriate for patients who fail biofeedback but wish to avoid surgery 2
• The injection provides a therapeutic window to attempt additional biofeedback retraining 2

Surgical Management

Indications for Surgery

• Surgery should be considered for patients who remain symptomatic after 3-6 months of conservative treatment failure 2, 3
• Patients with anal hypertonia-associated anismus are particularly appropriate surgical candidates 3

Surgical Technique

• Partial division of puborectalis muscle combined with tailored lateral internal sphincterotomy on the contralateral side is the most effective surgical approach, achieving 89% symptom improvement at 12 months 3
• This combined technique produces significant reduction in modified Altomare constipation scores from 16.4 ± 1.7 to 6.6 ± 1.0 at 12 months (p < 0.0001) 3
• Surgical outcomes are superior to both biofeedback (70% vs 30% success at 1 year) and botulinum toxin (70% vs 35% success at 1 year) 2
• Complication rate is low at 6.5%, with only minor complications reported 3

Treatment Algorithm

1. Initial 3-month trial of biofeedback therapy for all patients 1, 2

   • Consider psycho-echo-biofeedback if anxiety/depression present 5
   • Consider adding acupoint thread embedding for enhanced efficacy 1

2. If symptoms persist after 3 months of biofeedback:

   • Botulinum toxin injection for temporary relief or as bridge therapy 2
   • OR proceed directly to surgical evaluation if patient prefers definitive treatment 2, 3

3. Surgical intervention if conservative measures fail after 3-6 months:

   • Partial division of puborectalis muscle with contralateral lateral internal sphincterotomy 3

Critical Pitfalls to Avoid

• Do not delay treatment in patients with symptom duration exceeding 3 years, as biofeedback success rates decline significantly with longer symptom duration 4
• Do not rely solely on botulinum toxin for long-term management, as efficacy drops dramatically after 1 year 2
• Previous anorectal surgery significantly reduces biofeedback success, warranting earlier consideration of surgical options in these patients 5
• Do not perform extensive pre-treatment imaging to identify associated pelvirectal disorders, as their presence does not predict biofeedback failure 4