A passing affair

John is a 70-year-old retired man who presents after a spontaneously resolving episode of ureteric colic.

He had one previous episode at age 45 which required surgical intervention. The main constituent of a stone sent for analysis at that time was calcium oxalate.

John has normal kidney function and no other relevant clinical history. His father, two brothers and only sister all suffer from kidney stones.

Recurrence risk

Kidney stones affect 5-15% of the population. Following an initial episode of ureteric colic, the risk of recurrence is 5-15% within the first