Risk of Fecal Incontinence Associated with Superficial Anorectal Procedures

Lateral Internal Sphincterotomy

• The principal postoperative complication of lateral internal sphincterotomy is fecal incontinence rather than autonomic nerve injury, with reported rates of 2–12% in patients undergoing sphincter manipulation【1】.
• Adding a lateral internal sphincterotomy to hemorrhoidectomy increases the incidence of postoperative incontinence compared with hemorrhoidectomy alone【1】.

Hemorrhoidectomy‑Related Incontinence

• Immediate postoperative fecal incontinence occurs in 2–12% of patients after hemorrhoidectomy when the anal sphincter is manipulated【1】.
• Ultrasonography and manometry identify sphincter defects in up to 12% of patients following hemorrhoidectomy, indicating structural compromise of the anal sphincter complex【1】.
• Excessive retraction and extensive anal canal dilation during hemorrhoidectomy are identified as key technical factors that cause sphincter injury and subsequent incontinence【1】.

Fissurectomy versus Sphincterotomy

• Open and closed lateral internal sphincterotomy achieve higher healing rates than fissurectomy for chronic anal fissure, while fissurectomy completely avoids intentional sphincter division【2】【3】.

Botulinum Toxin for Chronic Anal Fissure

• Injection of botulinum toxin into the internal anal sphincter yields cure rates of 75–95% for chronic anal fissures without introducing permanent incontinence or sexual dysfunction【4】.
• Botulinum toxin should be considered after at least 8 weeks of unsuccessful topical therapy and before proceeding to any sphincterotomy【4】.

Fistulotomy in Crohn’s Disease

• In patients with low perianal fistulas secondary to Crohn’s disease who have no active rectal inflammation, fistulotomy provides superior healing compared with alternative approaches; however, the use of cutting setons carries a 57% risk of postoperative incontinence due to forced sphincter transection and is therefore strongly discouraged【5】.

Lateral Sphincterotomy and Fistulotomy Complications

Anatomical Considerations

• The American College of Surgeons notes that lateral internal sphincterotomy and fistulotomy are superficial procedures that involve only the anal sphincter muscles at the anal canal level, and do not approach the deep pelvic autonomic nerves responsible for sexual and ejaculatory function 6
• The American Urological Association states that ejaculatory function is controlled by deep pelvic autonomic nerves (hypogastric plexus, pelvic splanchnic nerves) located several centimeters away from the surgical field 6

Post-Sphincterotomy Complications

• The American Society of Colon and Rectal Surgeons reports that neuropathic pain and dysesthesia, rather than structural sphincter or nerve damage, can occur after lateral sphincterotomy 7, 6
• The International Society for the Study of Women's Sexual Health notes that pelvic floor muscle tension and protective guarding patterns can develop during the painful fissure period and persist after surgery 7, 8, 6

Management of Post-Sphincterotomy Sexual Discomfort

• The American Urological Association recommends initiating specialized pelvic floor physical therapy 2-3 times weekly, focusing on internal and external myofascial release, gradual desensitization exercises, and muscle coordination retraining 7, 8, 6
• The American Pain Society suggests applying topical lidocaine 5% ointment to affected areas for neuropathic pain management 7, 6

Documented Complications

• The American Gastroenterological Association states that incontinence occurs in 2-12% of patients after hemorrhoidectomy with sphincter manipulation 9, 10

Alternative Therapies

• The American Society of Colon and Rectal Surgeons notes that botulinum toxin injection achieves 75-95% cure rates for chronic anal fissures with no risk of permanent incontinence or sexual dysfunction 7, 6

Risk of Repeat Anal Procedures After Prior Fistulotomy

1. Cumulative Sphincter Injury from Repeat Procedures

2. Conservative Management Recommendations

3. Sphincter‑Preserving Surgical Options

4. Sphincteroplasty Technique Considerations

5. Long‑Term Outcomes of Sphincteroplasty for Established Incontinence

6. Critical Pitfalls to Avoid

Age‑Related Incontinence Risk and Sphincter‑Preserving Strategies

Age‑Related Risk

• Advanced age is consistently linked to a higher likelihood of fecal incontinence after any procedure that compromises the anal sphincter, because age‑related degeneration of sphincter muscle adds to the functional loss caused by surgery. [15][16]

Sphincter‑Preserving Surgical Options

• The Ligation of Intersphincteric Fistula Tract (LIFT) technique preserves sphincter anatomy and yields a 65 %–77 % fistula‑healing success rate; however, approximately 16 % of patients may still experience a worsening of continence after the procedure. 17

Long‑Term Prognosis

• In patients with a prior low transphincteric fistulotomy involving ~30 % sphincter division, continence is expected to remain stable provided no additional sphincter trauma occurs, but the natural aging process will increase susceptibility to incontinence from future insults such as diarrheal illness, further surgery, or neurologic disease. [15][16]