To update -- he claims he's tried all these things and they haven't worked. Whether or not I believe him is another story. I'm sure he's tried goldenseal root before. *rolls eyes* I feel like he doesn't really want to put the work in to get himself healthy and I'm wasting my time at this point.
I just tested myself using one of those at home UTI test kits and I came back as clear as can be. I don't know how reliable those are exactly, but I seem to be in the clear. Earlier he told me that this is an issue no matter who he has sex with though, so I don't think it's specifically me.
With that being said, if it's not me and he really has tried all these methods (even though he eats fast food and drinks soda on a consistent basis), it really just doesn't make any sense as to what's causing them. I've read somewhere prostate problems or kidney stones, but I don't know.