Table 5. The relationship between food groups and stone expulsion .

Type of food	Spontaneous stone expulsion duration 1 year
	Correlation coefficient	p
High- potassium fruits	0.03	0.73
High-oxalate foods	-0.1	0.26
High-oxalate drinks	0.26	0.005*
High-calcium foods	-0.13	0.15
High- sodium foods	0.15	0.10
High- purine foods	0.063	0.51
High- fructose drinks	0.18	0.048*
High-magnesium foods	0.03	0.7
Caffeine	-0.033	0.73

*Significant with p<0.05 based on Pearson-coefficient (p < 0.05).