Background: It is uncommon for emergency physicians to discover a patient with circulatory failure resulting from chronic diarrhea.

Objective: We describe McKittrick-Wheelock syndrome, a rare disorder characterized by volume and electrolyte depletion and caused by colonic neoplasm.

Methods: The case of a 30-year-old woman who came to the Emergency Department with hypovolemic shock, hyponatremia, and hypokalemia with a background of chronic diarrhea is reported. The hypokalemia and dehydration were refractory to aggressive replacement therapy. Her condition was the result of fluid and electrolyte hypersecretion caused by a colonic adenocarcinoma and colonic polyposis. Surgical removal of the colon and subsequent volume and electrolyte replacement therapy resulted in complete recovery.

Conclusions: This case is presented to increase awareness among emergency physicians of the rare disorder of McKittrick-Wheelock syndrome.