gallstone - A stone that grows in your bladder and decides when it's goi

A stone that grows in your bladder and decides when it's going to leave or cause you to scream like a banshee

My gallstone came out during a yoga class and I had to leave mid-pose.

I passed a gallstone in the middle of a meeting and my boss thought I was having a breakdown.

My gallstone came out while I was eating a taco, and it was the worst thing ever.