They are most definitely genetic.
I've had one. And I'm determined to never have one again. I work for a large health related company (
www.webmd.com) and have read ridiculous amounts on them. It's not just from dehydration/lack of water. All kinds of healthy (and some not so healthy) foods can also contribute to them. dark chocolate, tea, sugary drinks, spinach, instant coffee....all sorts of things!
When I had mine, the nurse in the ER said it was close to coming out and would only be a few hours...well, apparently mine was as stubborn as I am as it took over a MONTH for it to come out. And when it did, it was the most anti-climactic thing ever
but I was glad that it came out.
One of my former coworkers (female) has had both stones and children. She said the pain you get with a kidney stone is on par with that of childbirth. It's most definitely the closest men can get to having a baby...