Lateral Internal Sphincterotomy Does NOT Prevent Hemorrhoid Recurrence and May Worsen Outcomes
Lateral internal sphincterotomy (LIS) should NOT be performed as an adjunct to hemorrhoidectomy or as a preventive measure for hemorrhoid recurrence in patients with chronic constipation and hemorrhoids. Randomized studies have definitively shown that adding LIS to hemorrhoid surgery does not improve outcomes and actually increases the incidence of fecal incontinence 1.
Why LIS Is Contraindicated for Hemorrhoid Prevention
Evidence Against LIS as Hemorrhoid Adjunct
Randomized controlled trials have explicitly demonstrated that lateral internal sphincterotomy provides no benefit when added to hemorrhoid excision 1.
Instead of helping, LIS increases postoperative incontinence rates when combined with hemorrhoidectomy, creating a composite sphincter injury from both the hemorrhoidectomy-related trauma and the sphincterotomy itself 1, 2.
Hemorrhoidectomy alone already carries up to 12% risk of sphincter defects documented by ultrasonography and anal manometry, caused by excessive retraction and dilation during the procedure 1, 2.
The Mechanism Problem
LIS treats anal fissures by reducing internal sphincter hypertonia—a pathophysiology completely unrelated to hemorrhoid formation 3, 4.
Hemorrhoids develop from vascular engorgement, straining, and increased intra-abdominal pressure, not from sphincter spasm 5.
Cutting the internal anal sphincter does nothing to address the venous congestion, prolapse, or bleeding that characterize hemorrhoidal disease 1, 5.
The Correct Approach: Treating the Root Cause
Address Constipation Directly
The actual solution for preventing hemorrhoid recurrence in a patient with lifelong constipation is aggressive management of the underlying bowel dysfunction, not sphincter surgery 5, 4.
Increase dietary fiber to 25-30 grams daily using bulk-forming agents like psyllium husk (5-6 teaspoons with 600 mL water daily) to produce soft, bulky stools that pass without straining 5.
Ensure adequate fluid intake to soften stool and reduce the need for straining during defecation 5.
Avoid prolonged sitting on the toilet and straining, which are the primary mechanical factors that cause hemorrhoid formation and recurrence 5.
Pharmacologic Adjuncts
Oral flavonoids (phlebotonics) can reduce bleeding, pain, and swelling, though 80% of patients experience symptom recurrence within 3-6 months after stopping 5.
Osmotic laxatives such as polyethylene glycol or lactulose can be used safely for chronic constipation management 5.
Surgical Management When Needed
If hemorrhoidectomy is required for grade III-IV hemorrhoids, perform conventional excisional hemorrhoidectomy (Ferguson or Milligan-Morgan technique) WITHOUT adding LIS, which achieves 90-98% success rates with 2-10% recurrence 1, 5.
For persistent grade I-III internal hemorrhoids after conservative management fails, rubber band ligation is the first procedural intervention, with success rates of 70.5-89% and no sphincter injury risk 5.
Critical Pitfalls to Avoid
Never perform anal dilatation as an adjunct to hemorrhoid surgery—it causes sphincter injuries and results in 52% incontinence rate at 17-year follow-up 1, 5.
Do not attribute all anorectal symptoms to hemorrhoids—anal fissures occur in up to 20% of patients with hemorrhoids and require different treatment 5.
Recognize that LIS is indicated ONLY for chronic anal fissure (>8 weeks duration) that has failed 8 weeks of conservative topical therapy, not for hemorrhoid prevention 6, 4.
Long-Term Incontinence Risk of LIS
Even when LIS is performed for its correct indication (chronic anal fissure), 45% of patients experience some degree of fecal incontinence at some point postoperatively, with women affected more than men (53.4% vs 33.3%) 7.
Although most incontinence is transient, at long-term follow-up (mean >5 years), 6% still report flatus incontinence, 8% have minor soiling, and 1% experience loss of solid stool 7.
In the context of hemorrhoid surgery, where LIS provides no benefit, exposing the patient to these incontinence risks is unjustifiable 1, 7.
The Bottom Line
The patient's lifelong constipation—not sphincter hypertonia—is driving hemorrhoid formation and recurrence. Performing LIS would subject him to permanent sphincter division and incontinence risk without addressing the actual problem 1, 7. Focus instead on aggressive fiber supplementation, adequate hydration, avoidance of straining, and appropriate hemorrhoid-specific interventions (rubber band ligation or hemorrhoidectomy when indicated) to prevent recurrence 5, 4.