• Stone disease is very prevalent. It is estimated that 10% of the population will develop stone disease in their lifetime. A person who develops a kidney stone has a 50% risk of developing another stone in the next 10 years.

Yes. There are various types of stones – calcium oxalate, uric acid, triple phosphate, calcium phosphate and cystine stones.

Uric acid stones that are small can be dissolved with medication if they do not cause obstruction (pain, fever).

Recurrent stone formers should get their stone analysed to evaluate the type of stone. They must also get a 24 hour urine analysis to evaluate why they are forming recurrent stones.

General advice is to drink plenty of water, reduce salt in the diet and reduce animal protein. It is important to have a normal intake of calcium.

A high intake of animal protein can increase stone formation. Avoid large quantities of meat, eggs and dairy products.

Do not add salt to your food at the table.

Tips to help you increase your fluid intake:

• Drink water at regular intervals
• Keep a bottle of water with you
• Add slices of lemon, lime or orange to make it more palatable
• Eat more fruit and vegetables – as they contain more water

Specific advice for certain stone types –

1. Calcium oxalate stones – avoid excessive consumption tea, coffee, nuts (almonds), seeds (peanuts), cocoa, chocolate, certain fruits (figs, plums, berries, tangerines, currants), rhubarb, vegetables (beetroot, celery, spinach, leeks, parsley, okra), soy products and fizzy drinks with high quantities of oxalates such as Coca cola, other aerated beverages.

2. Uric acid stones – avoid excessive consumption of animal protein such as red meat, fish (crab, mackerel, anchovies, sardines, shrimps), yeast extracts, beer, spinach, mushrooms, asparagus, legumes and cauliflower.

Individuals who are overweight also have high production of uric acid, therefore losing weight is beneficial.

3. Triple phosphate stones – these are usually due to urinary tract infection with bacteria such as Proteus, E coli, Pseudomonas and needs treatment of infection and stone removal.

4. Calcium phosphate stones – occur in those with Renal tubular acidosis and requires consultation with a nephrologist.

5. Cystine stones – these occur in patients who have a genetic disorder called Cystinuria. The patient and their family members need to be tested and counseled.

There are three treatment options –

Stones can be treated provided patients do not have a concurrent infection. If there are signs of infection (fever, chills, etc) then drainage of the kidney as a temporary measure is necessary followed, at a later date, by definitive treatment of the stone.

1. ESWL (Extracorporeal shock wave lithotripsy) – the stone is broken using sound waves and the resultant stone fragments are passed along with the urine. This procedure can be used in small radio-opaque (those seen on X-ray) stones.

ESWL cannot be done in pregnancy, patients on blood thinning medication (eg warfarin, xarelto, dabigatran, clopidogrel, brillanta), very overweight individuals.

2. Ureteroscopy and lithotripsy – this involves passing a fine telescope via the urinary tract and fragmenting the stone using either a manual stone breaking device or a holmium laser. The fragments are either retrieved using a basket or are small enough to be passed in the urine. This procedure can be utilized for most stones.

3. PCNL (Percutaneous nephrolithotomy) – this involves puncturing the kidney via a small hole in the back and extracting the stone fragments after breaking the stone. This procedure is usually reserved for large stones or stones in calyceal diverticula (small pockets in the kidney).