If a person is in a hospital, then medical personnel will filter the urine. It is important not to add anything to the stone, such as tissue or tape, as this can make testing more difficult. If a stone is found, it is placed into the clean container, allowed to dry, and returned to the laboratory or doctor as instructed. You will be asked to examine the mesh for any particulates, keeping in mind that stones may be easily visible or as small as grains of sand. You will need to filter all of your urine because there is no way to determine exactly when a stone will pass out of the body. Your doctor or pathology collection centre will provide you with a clean container and a straining device that has a fine mesh. Small stones can be passed in the urine and it's possible to collect them at home. Drug-related - stones that are associated with drugs such as guaifenesin, indinavir, triamterene, atazanavir, and sulfa drugsĪccording to Kidney Health Australia about 4% to 8% of Australians suffer from kidney stones at some time.Cystine - stones associated with an inherited excess of cystine excretion.About 75% of stones will contain calcium. These four types make up about 95% to 99% of kidney stones. Struvite (magnesium ammonium phosphate) - stones associated with a bacterial infection.It may be made of just one chemical compound or have different chemicals in different layers. The composition of the stone depends on the chemicals present in excess. It can range in size from a grain of sand to bigger than a golf ball. Depending on how much and what type of substance crystallises and where it forms, a kidney stone may be round, sharp and pointy or irregular with branches (called a staghorn). It can also occur when someone does not drink enough over a period of time and has more concentrated urine because there is less water in it. This can happen when someone produces and excretes an excess amount of the substance. Most often they occur when there is a high concentration of a particular chemical substance in the urine that precipitates and forms crystals. The stone is broken into very small fragments that can pass through the urinary tract. This treatment pulverises the stone in place using targeted shock waves. With some stones, it is possible to use extracorporeal shock wave lithotripsy. The stone may need to be surgically removed, often using devices that pass through the urethra and bladder to the site of the stone.

With very large stones, which typically cannot pass from the kidney into the ureters, and for smaller stones that get into but do not pass through the ureters, some form of treatment is needed. Many stones will eventually pass out of the body in the urine, but some are too large or have too irregular a shape for the body to expel. Source : National Institute of Diabetes and Digestive and Kidney Diseases

Tissue fragments in urine