Idiopathic adulthood ductopenia (IAD) is a chronic small duct cholestatic biliary disease that is characterized by the loss of interlobular bile ducts. It is diagnosed when there is biochemical evidence of cholestatic liver disease, ductopenia on liver biopsy, and no other identifiable cause of cholestasis. We present a patient with 10 days of progressive abdominal pain, jaundice, and worsening liver function tests who advanced to fulminant liver failure with no apparent underlying cause. He was found to have cirrhosis, with biopsy demonstrative of ductopenia, consistent with idiopathic adulthood ductopenia, which is a rare etiology of cirrhosis but should be considered when the typical workup yields no answer. | Idiopathic adulthood ductopenia causing cirrhosis