Summary and ConclusionsThree cases of villous adenomas of the rectum are presented. All patients had severe fluid and electrolyte imbalance secondary to the loss of mucus. Two patients died because fluid replacement was impaired by severe congestive heart failure that made surgical therapy impossible.A vigorous approach to correction of fluid and electrolyte imbalance is imperative, and surgical removal of the mucussecreting tumor should be performed as soon as the imbalance is corrected.Sodium loss raises the question of its effect on aldosterone secretion. The loss of mucoitin sulfuric acid also suggests the possibility of sulfur loss.