Abstract
RATIONALE: Recurrent anal fistula remains a clinical challenge, especially when standard treatment fails to prevent relapse. Adjacent cystic infections may represent an underrecognized contributor to persistent or recurrent disease. PATIENT CONCERNS: A patient with a long-standing history of perianal discomfort and multiple anal fistula recurrences presented with ongoing discharge and pain despite previous surgical interventions. DIAGNOSES: Clinical examination and intraoperative findings revealed a 2 × 2 cm infected cyst located adjacent to the recurrent anal fistula tract. INTERVENTIONS: The patient underwent complete surgical excision of both the anal fistula and the adjacent infected cyst. OUTCOMES: Postoperative recovery was uneventful. The patient achieved sustained remission with no signs of recurrence observed during a 3-month follow-up period. LESSONS: This case highlights a notable association between recurrent anal fistula and adjacent cystic infection. Cystic infection may serve as a hidden trigger for fistula reactivation and should be considered in patients with treatment-resistant perianal disease.