Stones caused by urinary tract infections are clinically known as “infection stones”. Its mineralogical name is “guano stone” and its main crystalline components are magnesium ammonium phosphate hexahydrate and apatite carbonate. The most common pathogenic bacterium is Mycobacterium avium. This urease-producing bacterium breaks down urea into ammonia and carbon dioxide. After ammonia is synthesized into ammonium hydroxide by water, the urine pH rises significantly, and when the pH reaches 7.2, ammonium combines with magnesium and phosphate in the urine to form magnesium ammonium phosphate. Also in this alkaline urine, calcium and phosphate are induced to chemically synthesize apatite and combine with carbon dioxide from urea to form carbonate apatite. When these lithogenic substances reach supersaturation, crystals will also form rapidly. At the same time, ammonia produced by bacteria is able to destroy the protective layer of glucosaminoglycan on the epithelial mucosal surface, facilitating the crystallization of magnesium ammonium phosphate and bacterial adhesion to the urinary epithelium. It should be noted that etiologically, stones caused by such infections are different from stones complicated by infections, which are mostly E. coli infections, which generally do not produce detoxifying enzymes.