Editing Kidney stone disease (section)

==== Struvite stones ====
About 10–15% of urinary calculi are composed of [[struvite]] (hexa-hydrated [[ammonium magnesium phosphate]], NH<sub>4</sub>MgPO<sub>4</sub>·6H<sub>2</sub>O).<ref name=Heptinstall2007 /> Struvite stones (also known as "infection stones," [[urease]], or triple-phosphate stones) form most often in the presence of infection by urea-splitting [[bacteria]]. Using the enzyme urease, these organisms [[Metabolism|metabolize]] [[urea]] into [[ammonia]] and [[carbon dioxide]]. This [[alkalinity|alkalinizes]] the urine, resulting in favorable conditions for the formation of struvite stones. ''[[Proteus mirabilis]]'', ''[[Proteus vulgaris]]'', and ''[[Morganella morganii]]'' are the most common organisms isolated; less common organisms include ''[[Ureaplasma urealyticum]]'' and some species of ''[[Providencia (bacterium)|Providencia]]'', ''[[Klebsiella]]'', ''[[Serratia]]'', and ''[[Enterobacter]]''. These infection stones are commonly observed in people who have factors that predispose them to [[urinary tract infection]]s, such as those with [[spinal cord injury]] and other forms of [[neurogenic bladder]], [[ileal conduit urinary diversion]], [[vesicoureteral reflux]], and [[Obstructive uropathy|obstructive uropathies]]. They are also commonly seen in people with underlying metabolic disorders, such as [[idiopathic]] [[hypercalciuria]], [[hyperparathyroidism]], and [[gout]]. Infection stones can grow rapidly, forming large calyceal staghorn ([[antler]]-shaped) calculi requiring invasive surgery such as percutaneous nephrolithotomy for definitive treatment.<ref name=Heptinstall2007 />

Struvite stones (triple-phosphate/magnesium ammonium phosphate) have a 'coffin lid' morphology by microscopy.<ref name="De Mais" />