<prompt> All are true about hypernatremia due to diarrhoea exceptSerum osmolality 295 mOsmkgSecretory diarrheaUrine with osmolality 800 mOsmkgIncreased circulating AVP  <response>: Notably, osmotic diarrhoea and viral gastroenteritis typically generate stools with Na and K 100 mM, thus leading to water loss and hypernatremia; in contrast, secretory diarrhoea typically results in isotonic stool and thus hypovolemia with or without hypovolemic hyponatremia. The appropriate response to hypernatremia and a serum osmolality 295 mOsmkg is an increase in circulating AVP and the excretion of low volumes 500 mLd of maximally concentrated urine, i.e., urine with osmolality 800 mOsmkg; should this be the case, then an extrarenal source of water loss is primarily responsible for the generation of hypernatremia. as in diarrhoea Ref: Harrison 19e pg: 304 