The document provides an extensive overview of fistulas, abnormal connections between organs or epithelial surfaces, covering their introduction, epidemiology, etiology, pathophysiology, classification, risk factors, clinical presentation, diagnosis, complications, and management strategies. It discusses various types of fistulas and emphasizes the importance of timely diagnosis and individualized treatment to improve patient outcomes and quality of life. Additionally, the role of pharmacists in managing medications for fistulas is outlined.