Long-term outcomes of intramural rectal botulinum toxin injections for urge fecal incontinence: a salvage therapy for sacral neuromodulation nonresponders?

PURPOSE: Sacral neuromodulation (SNM) failure in fecal incontinence (FI) management represents a therapeutic challenge, often leading to more invasive, less accepted alternatives with inconsistent efficacy. In this context, intramural rectal botulinum toxin A (BoNT-A) injection has recently emerged as a promising minimally invasive alternative for urge FI. This study aimed to evaluate the effectiveness of intramural rectal BoNT-A injections in the challenging subgroup of SNM nonresponders. METHODS: This retrospective, single-center study included patients with urge FI who underwent intramural rectal BoNT-A injections after SNM failure, between February 2018 and September 2024. The procedure involved endoscopic injection of 200 units of BoNT-A at 10 circumferential sites in the rectal wall. Treatment efficacy was assessed using the Cleveland Clinic Fecal Incontinence Score (CCFIS) and a visual analog scale (VAS) for symptom severity. RESULTS: Fifteen female patients met the inclusion criteria, with a median follow-up of 22.5 months (range, 4.4-103.2 months). Patients received a median of 2 injections, with a median reinjection interval of 9.8 months. CCFIS scores demonstrated significant improvement (median, 15 [range, 8-20] vs. 8 [range, 0-20]; P=0.001), as did VAS symptom scores (median, 4 [range, 0-5] vs. 2 [range, 0-5]; P=0.001). No adverse events were reported. CONCLUSION: This study provides long-term evidence supporting intramural rectal BoNT-A injections as an effective option for managing urge FI, including as salvage therapy in SNM nonresponders. Further studies are necessary to confirm these findings and define the optimal role of BoNT-A within the therapeutic algorithm for urge FI.