McKittrick-Wheelock syndrome is a rare disease when villous adenoma of the distal colon predisposes to profuse watery diarrhea with subsequent severe electrolyte disturbances and acute renal damage. A differentiated approach to correct diagnosis requires in-depth pathophysiological knowledge of regulation of water-electrolyte metabolism, functional and organic disorders of gastrointestinal tract and clinical manifestations of hypoosmolar dehydration. The peculiarity of the McKittrick-Wheelock syndrome is a 100% probability of death without treatment and complete regression of symptoms under complex correction of homeostasis and total resection of tumor. We demonstrate the main clinical trends of the McKittrick-Wheelock syndrome. This report may be useful for general practitioners, gastroenterologists, oncologists, nephrologists and anesthesiologists.