McKittrick-Wheelock syndrome: a rare cause of diarrhoea.

McKittrick-Wheelock syndrome is a rare disorder caused by fluid and electrolyte hypersecretion from a rectal tumour. The most frequently reported tumours are villous adenomas. Dehydration with severe hyponatremia, hypokalemia, metabolic acidosis, acute renal failure and watery diarrhoea is typical. The authors present a case of McKittrick-Wheelock syndrome caused by rectal adenocarcinoma.