I get back pain and then it will stop when I urinate , but my urine is brown. It does not happen all the time. So I need to get the sample when it happens.
Hopefully you are seeing a urologist, as brown urine is not a good thing. It can be the signal of something as simple as dehydration or something far worse such as liver failure. While online advice is great for asking the questions of your doctor, nothing takes the place of your doctor's advice.
As far as storage, the best thing I have seen is to make your collection and see your doctor as soon as possible, even the same day. Urine that has no bacteria or infection is sterile while in the body but begins to deteriorate as soon as it reaches air. Urine that has been collected and stored is less likely to produce accurate results in testing.
I have read, but can not substantiate, that urine can be kept in a cool room temperature environment for 24 hours. Refrigerating and/or freezing can kill the bacteria that the urine test is supposed to detect and unless recommended by your doctor is not something you want to do.
Good luck and let us know how you are doing!Vicki M