Hey sci...really inexperienced in UTIs and Remi, but had some thoughts just to bounce around.
1) I know you had/have a fistula. Is it possible you have a fistula affecting your urinary tract? That would create a perfect envirtonment for ongoing UTIs
2) I had drastically brown pee when I had severe gallstone issues - included with nausea/vomiting, pain in groin and lower back. Still have that gallbladder??? Could this be an issue??