These are rare in surgical practice, it is due to direct stimulation of
renal bicarbonate reabsorbtion. In the main this occurs when there is
excessive mineralo-corticoid activity; for instance due to the various
types of Cushing's (drugs, pituitary, adrenal, ectopic ACTH), Conn's
syndrome ( primary,
liquorice, carbenoxalone), and rare syndromes (Liddle's, Bartter's,
and
hydroxylase
deficiencies).