Abstract
McKittrick-Wheelock is a rare syndrome characterized by a severe, difficult to correct electrolyte imbalance, chronic mucus diarrhea, and a large rectal polyp. In this case report, we describe an elderly patient diagnosed with a large nonmalignant rectal polyp during a routine colonoscopy 10 years prior to admission. For years, the patient has suffered from diarrhea, causing episodic life-threatening hypokalemia and hyponatremia with several unsuccessful attempts at endoscopic polyp removal. Due to symptomatic cholelithiasis, the patient was transferred to the surgical ward and diagnosed with McKittrick-Wheelock syndrome. The patient had undergone cholecystectomy and, after a period of preoperative preparation, underwent an abdominoperineal resection of the rectum. Histopathologic evaluation revealed a low-grade (G1) rectal carcinoma. This case report highlights the importance of a careful assessment of patients with electrolyte level disturbances, with some, albeit very rarely, requiring surgical intervention.