<prompt> Stag horn calculi associated with Proteus infection are?Uric acid stonesTriple phosphate stonesCalcium oxalate stonesCysteine stones  <response>: Triple phosphate or struvite Calcium phosphate with ammonium magnesium phosphate is smooth and diy white. It grows in alkaline urine, especially when urea splitting organisms like proteus are present and break urea to ammonia and co2 and make urine alkaline. they enlarge to fill most of the collecting system forming a staghorn calculus. Reference : Bailey and Loves sho practice of surgery 27th edition , chapter 76 , pg no 1406 