In some cases (like mine about 2 years ago) the first flush is only tip of the iceberg. The liver takes a push and starts to awaken, so stones from deep inside travel close to exits. Some of them are hard and irregular shape, because they had to take the shape of the bile ducts. When moved to new places they don't fit any longer and might irritate duct walls. I guarantee at least some discomfort at some stage.
Things to help to get over it:
-active life style
-shake your liver (jogging, basketball, aerobics, rugby, play with your kids(or grad) in the park, walk your dog, use your imagination from here)
-massage your liver.
-place over the area hot water bottle to easy off pain.
-take a sauna session.
My first year I got out about 1 kg of stones. Most of them dark green. During that time I understood - I need to go deep into yoga, and now my rule is every day practice.
And I'd rather do this then being a passive part of money making medical industry.
Good luck to you, breathe nice and easy,