Here's some info from a site I like to use for general info, a site that uses the Harvard Medical School. There's lots info there on kidney stones.

Prevention

You can help to prevent kidney stones by drinking plenty of fluids so that you avoid dehydration. This dilutes your urine and decreases the chance that chemicals will combine to form stones.

After your doctor receives an analysis of the chemical composition of your kidney stones, he or she may be able to suggest a medication or changes in your diet that will help to prevent stones from forming in the future. Because certain medications may increase the risk of stones, your doctor may want to adjust your regular medications if you have had kidney stones.

If you have the most common type of stone, a calcium oxalate stone, you can help to prevent new stones from forming by eating an appropriate amount of calcium in your diet. Low-fat dairy products and other calcium-rich foods are recommended. Calcium in your diet binds oxalate inside the intestines to decrease the amount of oxalate that gets into the blood, so less spills into the urine. Although it is important to get enough calcium, too much calcium (for example, from a high dose of calcium supplements) can increase the risk of stone formation. If your 24-hour urine collection tests show that you excrete too much oxalate into your urine, you should avoid eating foods high in oxalate, including beets, spinach, chard and rhubarb. Tea, coffee, cola, chocolate and nuts also contain oxalate, but these can be used in moderation. Eating too much salt and meat can cause more kidney stones to form.

Please note those words IF YOU HAVE THE MOST COMMON TYPE OF STONE.

As for the beer, I believe alcohol dehydrates the body. Better lay off the beer.

As for the pain, I think both doctors were trying to say the same thing. Take a painkiller when the pain starts. Don't wait till it's really bad. Don't take it if you're feeling fine.

I'm sorry for your suffering. I hope it never happens again.