CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-23). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1422 · Search date 2026-07-23 · Methodology v0.6

Lateral internal sphincterotomy,
does it really help with Complete healing and prevention of recurrence in medically refractory chronic anal fissure?

30-Second Summary
B
Evidence Grade B · 75 · Safety caution
Healing is high in medically refractory chronic anal fissure, but patients must be selected with continence risk in mind
What the
research shows
Lateral internal sphincterotomy is rated B because it produces high complete-healing rates and low recurrence in chronic anal fissure that has not responded to medication. Small randomized trials showed faster and more complete healing than topical nitroglycerin, and six-year follow-up of a multicenter trial preserved the surgical advantage. ASCRS guidance summarizes healing of at least 88% for up to six years in selected patients. The trials are small and flatus or fecal incontinence remains a surgical risk, preventing an A.
What the
ads claim
A one-time permanent cure overstates the evidence. Recurrence is uncommon but possible, and informed consent must address temporary or persistent flatus and fecal incontinence alongside healing.
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Useful facts when choosing a product

  • Lateral internal sphincterotomy divides part of the internal anal sphincter to reduce resting pressure and improve blood flow and healing at the fissure.
  • It is considered for chronic fissure unresponsive to conservative and topical nitrate or calcium-channel-blocker therapy, not as first treatment for every acute fissure.
  • Flatus or fecal incontinence, bleeding, infection, pain, urinary retention, and delayed wound healing can occur; baseline incontinence, obstetric injury, and previous anorectal surgery require particular caution.
  • This is surgery for anal fissure and is distinct in disease and mechanism from MPFF used for hemorrhoidal symptoms.
Gap Measurement · Verdict 1422 · B 75
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Mishra 2005 randomized 40 participants to topical nitroglycerin or sphincterotomy; six-week healing was similar between groups, and the authors recommended nitroglycerin first with sphincterotomy reserved for severe pain or nonresponse at four weeks. Brown 2007 followed participants from an earlier multicenter randomized trial for about six years and confirmed superior long-term healing with surgery. ASCRS 2023 synthesized comparative studies and reviews and reports high healing in selected chronic fissure.

02

Why this is classified as B (75)

Comparative trials, long-term follow-up, and guidelines consistently support high healing and superiority to medication. Individual randomized trials remain small, selection matters, and recurrence and continence harm remain possible, supporting B with 75 points. Safety is assessed separately from efficacy.

Counterpoint. After medical failure, baseline continence and sphincter integrity can guide discussion of tailored sphincterotomy or a sphincter-preserving procedure.

Rejudgment record. New verdict — Accepted randomized comparisons with medication, six-year multicenter follow-up, and high healing summarized by ASCRS, while applying the ceiling for small trials in selected surgical patients

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Complete healing of chronic anal fissureBRandomized comparisons and guidance consistently show higher healing than medical therapy.
Lower long-term recurrenceBSix-year follow-up of a multicenter trial favored the durability of surgery.
Relief of pain and symptomsBSmall randomized trials observed faster symptom relief alongside healing.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Mishra R et al. 2005Prospective randomized comparative trial20Inadequately reportedSix-week symptom relief, fissure healing, and sphincter pressureSix-week healing was similar between groups; sphincterotomy relieved symptoms somewhat faster, but the authors concluded nitroglycerin first with sphincterotomy reserved.Direct comparison with a small sample
Brown CJ et al. 2007Six-year follow-up of a multicenter randomized-trial cohortAcademic study; details incompletely reportedSymptom recurrence, additional treatment, satisfaction, and continenceThe healing advantage of sphincterotomy over nitroglycerin persisted long term.Long-term durability evidence
Davids JS et al. 2023 ASCRS guidelineEvidence-based clinical practice guidelineAmerican Society of Colon and Rectal SurgeonsHealing, recurrence, and fecal incontinenceLIS is more effective than medical therapy in selected chronic fissure, with at least 88% healing for up to six years.Synthesis and applicability evidence
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-23).

Mishra R, Thomas S, Maan MS, Hadke NS. Topical nitroglycerin versus lateral internal sphincterotomy for chronic anal fissure: prospective, randomized trial. ANZ J Surg. 2005;75(12):1032-1035. PMID: 16398803. DOI: 10.1111/j.1445-2197.2005.03493.x.
checked
Brown CJ, Dubreuil D, Santoro L, Liu M, O'Connor BI, McLeod RS. Lateral internal sphincterotomy is superior to topical nitroglycerin for healing chronic anal fissure and does not compromise long-term fecal continence: six-year follow-up of a multicenter, randomized, controlled trial. Dis Colon Rectum. 2007;50(4):442-448. PMID: 17297553. DOI: 10.1007/s10350-006-0844-3.
checked
Davids JS, Hawkins AT, Bhama AR, et al. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Anal Fissures. Dis Colon Rectum. 2023;66(2):190-199. PMID: 36321851. DOI: 10.1097/DCR.0000000000002664.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-23 · Corrections: none

Cite this verdict

Lateral internal sphincterotomy x healing of medically refractory chronic anal fissure Evidence Grade B card
[Chamgap] Lateral internal sphincterotomy x healing of medically refractory chronic anal fissure — Evidence Grade B·75. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/gut/lateral-internal-sphincterotomy-refractory-chronic-anal-fissure-healing/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.