What could be causing a patient's decreased libido and ejaculation strength and pressure after undergoing lateral sphincterotomy, fissurectomy, and hemorrhoidectomy (grade 3) for a anal fissure and hemorrhoids, which were complications of a laxative overdose?

Pelvic Nerve Injury from Anorectal Surgery as the Likely Cause

The persistent decreased libido and ejaculation strength/pressure following lateral sphincterotomy, fissurectomy, and hemorrhoidectomy is most likely due to iatrogenic damage to the autonomic pelvic nerves during surgery, particularly affecting the hypogastric plexus and pelvic splanchnic nerves that control ejaculatory function and sexual response.

Mechanism of Sexual Dysfunction After Anorectal Surgery

Autonomic Nerve Damage

• Pelvic surgery, including anorectal procedures, can damage the autonomic nervous system controlling sexual function, leading to ejaculatory dysfunction, decreased libido, and reduced orgasmic intensity 1.
• The hypogastric plexus and pelvic splanchnic nerves lie in close proximity to the surgical field during lateral sphincterotomy and deep fissurectomy procedures, making them vulnerable to thermal injury, traction, or direct trauma 2.
• Peripheral nervous system lesions affecting genital organ innervation produce malfunction of genital response, including loss of genital sensitivity, ejaculation disorders, and orgasmic dysfunction 1.

Specific Surgical Risk Factors

• Lateral internal sphincterotomy, while effective for fissure healing (97.8% success rate), carries risks of autonomic nerve injury when dissection extends beyond the sphincter complex 3.
• The combination of three procedures (sphincterotomy, fissurectomy, and hemorrhoidectomy) increases the cumulative risk of nerve damage through extended surgical time, tissue manipulation, and potential thermal spread from electrocautery 2.
• Deep posterior fissures requiring fissurectomy may necessitate dissection closer to the pelvic floor and autonomic nerve pathways 3.

Clinical Presentation Consistent with Nerve Injury

Ejaculatory Dysfunction Pattern

• The specific complaint of decreased ejaculation pressure and strength, combined with reduced libido, is characteristic of autonomic nerve damage rather than vascular or hormonal causes 4.
• Unlike erectile dysfunction (which primarily involves vascular mechanisms), ejaculatory dysfunction specifically implicates sympathetic nerve pathways controlling seminal emission and bladder neck closure 4.
• The persistence of symptoms despite complete wound healing strongly suggests permanent nerve injury rather than temporary inflammation 1.

Differential Diagnosis Considerations

• Psychological factors alone would not typically cause isolated ejaculatory pressure changes without erectile dysfunction 4.
• Vascular injury would more likely present with erectile dysfunction as the primary complaint 4.
• The ongoing pelvic pain being treated with therapy may represent neuropathic pain from the same nerve injury causing sexual dysfunction 1.

Diagnostic Evaluation

Recommended Testing

• Serum testosterone levels should be checked to rule out hypogonadism, as cancer treatment and pelvic surgery can cause hormonal changes affecting libido and sexual function 4.
• Consider referral to urology or sexual health specialist for comprehensive evaluation including neurophysiologic testing to clarify peripheral nervous system involvement 1.
• Validated screening tools such as the Sexual Health Inventory for Men (SHIM) can quantify the degree of dysfunction 4.

Clinical Neurophysiology

• In patients with suspected denervation lesions of genital organ innervation within the lumbosacral spinal canal and pelvis, clinical neurophysiologic testing may clarify peripheral nervous system involvement 1.

Treatment Approach

Multidimensional Treatment Plan

• Treatment of sexual dysfunction requires addressing underlying issues guided by the specific type of problem, with referrals to specialists (psychotherapy, sexual/couples counseling, urology, sexual health specialist) as appropriate 4.

Pharmacologic Options

PDE5 Inhibitors

• PDE5 inhibitor treatment (sildenafil, vardenafil, tadalafil) has been shown to improve symptoms of erectile dysfunction and is well tolerated, though efficacy for isolated ejaculatory dysfunction is limited 4.
• Start conservatively with on-demand dosing and titrate to maximum dose as needed; daily low-dose treatment may also be effective 4.
• PDE5 inhibitors are contraindicated in patients taking oral nitrates due to dangerous blood pressure decreases 4.

Testosterone Therapy

• If hypogonadism is confirmed, testosterone therapy may relieve symptoms of ejaculatory dysfunction and decreased libido 4.
• The addition of testosterone to PDE5 inhibitor therapy in individuals with low serum testosterone may improve sexual function 4.

Bupropion for Libido

• Bupropion is specifically mentioned as an off-label option for hypoactive sexual desire disorder, with dosing of 100-150 mg daily (SR formulation) or 150 mg daily (XL formulation), titrated to maintenance doses 5.
• Morning administration is recommended due to activating properties that can cause insomnia 5.
• Consider long-term therapy as sexual dysfunction typically returns upon discontinuation 5.

Non-Pharmacologic Interventions

• Counseling and education on coping strategies can greatly benefit patients with sexual dysfunction from peripheral nervous system disorders 1.
• Pelvic floor physical therapy may help address concurrent pelvic pain and potentially improve sexual function 1.

Prognosis and Counseling

Expected Outcomes

• Permanent nerve injury from pelvic surgery may result in persistent sexual dysfunction that does not spontaneously resolve 1, 2.
• Unlike temporary inflammation or psychological factors, structural nerve damage has limited regenerative capacity in adults 1.
• Opening up discussion on sexual issues should be part of management, as sexual dysfunction can alter self-esteem and lower quality of life 1.

Critical Pitfall

• The most common error is attributing persistent sexual dysfunction solely to psychological factors or inadequate healing time, when the underlying cause is permanent nerve injury requiring specific interventions and realistic expectations 1.