In these 2 instances it was Watermelon seed. But I have used Celery seed in the past. Celery is good if you have uric acid based stones. I'm pretty sure mine are/were calcium oxalate stones b/c I used to be able to bring the pain on by consuming something high in calcium along with an oxalate source. Sometimes high oxalate foods alone would cause discomfort in that area.
My main remedies right now are the Watermelon Seed Tea (convenient), chianca piedra (effective), magnesium malate, drinking more water, lots of Watermelon -the fruit. Sometimes tomato juice seems to help, especially with a little parsley. And probably something else I'm forgetting. Hope this helps.