Don't know if this is why I woke up feeling so well this morning, but, over the past months my liver has been dropping a few stones into my gallbladder.
This has come from lemon juice and olive oil on copius salads, I feel.
The most recent big stone seems to be lodged in the duct, though not usually painful.
Yesterday I tried a tsp of Bragg's Apple Cider Vinegar on some fresh pineapple. The last of the juice in the dish, I added to some water and drank it. And I ate a little cucumber though the day, with some of my usual foods.
I read that ACV can break stones.
No idea what's happening in my gallbladder, but I sure feel good today.
Hope this helps your friend, along with all the other good suggestions here.