Surreptitious habitual vomiting simulating Bartter's syndrome.

A patient with hypokalemic alkalosis, normotensive hyperreninism, hyperaldosteronism, increased levels of urinary and plasma prostaglandin E, and vascular hyporesponsivity to angiotensin II was thought to have Bartter's syndrome. Results of a kidney biopsy showed hyperplasia of the juxtaglomerular apparatus but no renomedullary cell hyperplasia. A 24-hour urine collection showed a low chloride level and no increase in the fractional chloride clearance, thus excluding Bartter's syndrome. Subsequent disclosure of surreptitious, habitual vomiting explained the hypokalemia.