I've passed about 35 in my life. Passed one on Xmas morning this year, an hour or so of discomfort. This year, week of Thanksgiving I passed a whopper, 7mm. My wife actually took me to the er, I threw up for 4 hours nonstop. I drank a gallon of water and was barely dribbling out blood red urine. I ended up passing it while being admitted. I have a couple things I've used over the years that have helped. The first is called stonebreaker, its an herb and breaks up stones, you just need to be consistent with it, and I wasn't. The other is something that has helped me pass them once I know they're coming. Drink tons of water, and every 15 mins or so, jump straight up and come down stiff legged. Do that 4 or 5 times every 15 minutes, it definitely helps them move along.