Gallstones: What to expect?

So, what exactly is cholelithiasis? My doctor just scribbled it down on my paperwork today—it feels more like a placeholder diagnosis than anything else. He’s just my GP, so he sent me off for an abdominal ultrasound to get some actual answers.

Does anyone here actually know what this is?

Gallstones.

What exactly causes this kind of thing?

I guess some people just lean that way and others don't... there isn't really one clear reason why it happens...

There are risk factors and mechanisms involved—at least one of them. Do a quick search... I'd rather we don't clutter this thread with overly long and unnecessary posts here.