Silver Stool
A 69-year-old woman with metastatic colon cancer presented to the emergency department with a 2-week history of dizziness and unusually colored stool. She had no associated itching or darkening of the urine. The physical examination was notable for jaundice, hepatomegaly, and a diffusely tender abdomen. The rectal examination showed silver-colored stool (Panel A). Laboratory studies were notable for a hemoglobin level of 7.5 g per deciliter (reference range, 11.0 to 14.5), a total bilirubin level of 4.0 mg per deciliter (68 μmol per liter) (reference range, 0.2 to 1.3 mg per deciliter [3 to 22 μmol per liter]), and an alkaline phosphatase level of 369 U per liter (reference range, 45 to 117). Testing of the stool was positive for occult blood. Findings on computed tomography of the abdomen and pelvis included a cecal mass and multiple liver metastases (Panel B). The appearance of silver stool results from a combination of white stool associated with obstructive jaundice and black stool of melena. After a discussion of treatment options with the patient, a decision was made to focus on her comfort. She was discharged home with hospice care.