Renoduodenal fistulas are a rare and uncommon phenomenon that account for ˂1% of those found between the urinary and intestinal tracts. Precipitation of this pathologic tract can be caused by chronic inflammation, necrosis, or ischemia. This case illustrates a 72-year-old man presenting with flank pain discovered to have multiple renoduodenal fistulas and our approach that led to the resolution of his symptoms. We review the pathophysiology, management, and effects of these fistulous tracts on renal function. Patients with staghorn calculi should undergo immediate evaluation for removal of the stone. In cases complicated by fistula formation, need for radical nephrectomy should be investigated and surgical repair should be pursued.