Background: Complex fistula-in-ano presents significant surgical challenges, with inflammatory, mechanical, and microbiological factors contributing to recurrence. Mycobacterium abscessus, a multidrug-resistant nontuberculous mycobacterium (NTM), is typically associated with respiratory and skin infections but is rarely implicated in fistula-in-ano. This case highlights a rare presentation of Mycobacterium abscessus in recurrent complex anal fistula disease. Case Report: A 34-year-old man with complex anal fistula disease underwent multiple surgeries over 4 years. Recent surgical exploration revealed a collection in the left ischiorectal fossa and a sinus tract extending to the supralevator space, confirmed by MRI. Tissue curettings cultured Mycobacterium abscessus spp. massiliense, with histology showing non-necrotising granulomatous inflammation. Notably, the patient was a regular user of bidets, which may have facilitated the introduction of the bacterium, an organism ubiquitously present in natural water sources. He received a 4-week course of a combination of IV amikacin, cefoxitin, imipenem, and tigecycline, followed by 5 months of oral clofazimine and azithromycin. This regimen resulted in significant improvement, with follow-up MRI showing resolution of the collection and inflammation. Methodology and Results: A literature review of PubMed, Embase, Scopus, and Web of Science identified only one prior report of NTM in fistula-in-ano, emphasizing its rarity. Conclusion: Environmental exposure to Mycobacterium abscessus may contribute to refractory fistula-in-ano. Early recognition, microbiological diagnosis and tailored antibiotic therapy are vital to reducing morbidity and avoiding unnecessary surgical interventions.