Evelina, you are reporting excellent flush results here. Remember, that liver flushing isn't a magic bullet, but a process: eat healthy, flush every 2-4 weeks until you have 3 flushes in a row that are stone-free.
Finding what is causing your pain is as simple as journalling your food consumption. When you get into pain trouble, look at what you've eaten in the last 8 or so hours, find the consistant things and eliminate that food.