Kidney stones have become quite a painful health concern. A considerable number of people have been diagnosed with renal stone diseases during the recent past. Different advanced technologies are being used to diagnose and treat kidney stone diseases. The ‘Urine Lithogenic Test’ was founded by Dr. Susil W. Gunasekera, a former lecturer in Clinical Biochemistry and Nutrition, Faculty of Medicine, University of Peradeniya with the assistance of Dr. A.M.L. Beligaswatta, the Consultant Urologist of the General Hospital Kandy. This test is used to determine the tendency of the formation of renal crystals. This article therefore sheds light on this novel diagnostic method that could be used to check and diagnose people with renal stones.

What is this Kidney stone?
According to Dr. Gunasekera kidney stones are mineral deposits in the renal calyces and pelvis that are found free or attached to the renal papillae.  Renal stones contain crystalline and organic components and are formed when the urine becomes supersaturated with respect to a mineral. According to the research studies, approximately 80% of kidney stones compose of calcium oxalate, calcium phosphate, uric acid, magnesium, ammonium, phosphate and cystine. 

Types of Kidney Stones
There are 04 types of kidney stones based on chemical composition.

Calcium Oxalate : The principal chemical constituent of the commonest type of renal stone is Calcium oxalate – the Calcium salt of Oxalic acid. In fact, people with Calcium oxalate renal stone exceed 75% of the world’s renal stone disease population. Calcium Oxalate predominates amongst calculogenic chemicals for renal stones formation. Usually, a healthy person’s urine does not contain these oxalate crystals while occasionally, a few such crystals may be seen randomly.

The factors underlying the genesis of Calcium Oxalate renal stone are basically 

• Aberrant behaviours 
• Dietary aspects 
• Inadequate consumption of drinking water. (Excessively concentrated urine could contain higher levels of insoluble Calcium Oxalate, which would increase Calcium Oxalate crystals). 
• High levels of Fluoride in drinking water. 

Calcium Phosphate - Leads to formation of calcium phosphate stones.

Uric acid - More common in men than in women while this type of stone develops when urine is too acidic by a diet rich in purines (animal proteins, such as fish, shellfish, and meats). Moreover, uric acid kidney stones can occur in people with gout or those who are taking chemotherapy.

Cystine Stones - Researchers have identified mutations in two genes, SLC3A1 and SLC7A9, and which lead to the excretion of higher amounts of urinary cystine.

Struvite - A mixture of magnesium, ammonium, and phosphate and more prevalent in women than in men while main cause is chronic urinary tract infections by Proteus, Staphylococcus, Klebsiella and Pseudomonas. 

What is Urine Lithogenicity?
If a person has a family history of ‘renal stone disease’ or has a likelihood of developing renal stone disease it raises a doubt about whether that person’s urine is lithogenic or non-lithogenic. This could be found by conducting the Urine Lithogenic Test.  The Urine Lithogenic Test is a new Medical Laboratory Test. The test requires a ‘Mid-Stream’ sample of urine collected from the ‘first morning void’. The sample of urine is collected ideally in a sterile container.  A patient collecting the ‘first morning void’ must collect the urine urinated following waking up, ideally before having food or drinking fluids. A ‘Mid-Stream’ sample of the urine is obtained by passing out some urine (into the toilet bowl / urinal) uncollected and then collecting the urine next expelled. The container can be almost completely filled with the urine. The urine sample thus collected must be handed over to the Medical Testing Laboratory within 2-hours. This urine lithogenic test detects specific Gravity of urine, whether the urine is lithogenic or non-lithogenic, and if the urine is likely to be lithogenic or definitely lithogenic, the chemical identity of the lithogenic, Constituent/ Constituents. Moreover, this urine lithogenic test serves to determine patient compliance and efficacy of treatment to avert recurrence of renal colic /growth of renal calculi.

Minimising intestinal absorption of dietary oxalate
One needs to avoid consuming oxalate rich food such as Spinach, Beetroot, Okra, Amaranth, Potato, Beans & Nuts, Soya-based foods, Chocolate, Strong Black Tea, Tomato (ripened), Brinjal, Carrot, Yams, Wood apple and Gingelly seeds.

 Experimental findings in people with renal stones reveal that Lemon Juice was effective in preventing Calcium oxalate renal stone formation due to Hydroxy Citric Acid found in the juice of the Lemon fruit. Other than that, Citrus Family fruit juices have the ability to suppress the formation of new Calcium oxalate renal stones and solubilize Oxalate stones that had been formed.

The pulp of the Tamarind pod used in food had suppressed urinary Calcium oxalate crystal formation. 

Therapeutic properties of Phyllanthus niruri (Pitawakka plant) include treating renal stone diseases. Phyllanthus niruri is said to prevent the formation of calcium oxalate crystals in urine and also promote elimination of kidney and bladder stones.