I have not yet looked up all these things that some of you have posted about, but want to add this. My mother had repeated UTIs and kidney infections most of her adult life. I've always feared for her kidneys and now she has just one. Dr's never told her what was causing this (could just be bad kidneys), but one Dr told her she was not completely emptying her bladder, which leaves a little in there all the time, suseptible to infection. He told her to relieve herself, then sit there 5 min and try to go again, at least a couple of times. To my knowledge this has helped her a lot. Along w/ her cranberry juice daily, and often plain cranberries.
I figured out that I had been doing this already out of need, mostly at bedtime. Because I got tired of relieving myself, getting up and getting in bed, then feeling like getting up and going again, sometimes several times before I could stop and go to sleep. You will laugh, but my last pee of the day usually takes me about 20 minutes! (I use that time to read, usually). I believe that this has kept me from getting infections, I think I've only had 2 in my life, none went to my kidneys.
This is too personal, but maybe will help others. about 5 times, I 'empty', then sit a few minutes and squeeze out a little more. Takes a lot of concentration on those muscles! Somehow I can tell when it's all gone enough and I can finally go to bed and not have to get right back up.
And about the Amiltryp -- It is also precribed for bedwetting, because it makes it more difficult to empty the bladder. So kids that have the problem of involuntarily emptying their bladder in the nite, depending on the reason, amiltryp often helps them, at least until the problem resolves.