i included a link to NHS CHOICES WEBSITE for Methenamine Hippurate that has gone to moderation.
Like Duffcooper I also have to self-catheterize 4-5 times daily and was prone to repeat UTI.
I went the usual NHS gamut of various antibiotic protocols but long term low dose, and short term high dose then long term high dose and even though I was methodical in following Dr's orders I still developed antibiotic resistance and found there were no antibiotics left that would resolve the problem.
At this point I turned to the internet and found some research by M Zasloff
"Antimicrobial peptides, innate immunity, and the normally sterile urinary tract."
the full text is online free if you search using the title.
Making your own antimicrobial peptides as required means your body is better able to deal with infection before it gets a hold.
Vitamin D3 is required to upregulate these antimicrobial peptides. If you want to understand more there is a paper here
"Human antimicrobial peptides and proteins."
that is free full text online.
I found I needed to get my Vitamin D3 level up above 125nmol/l to get totally rid of repeat UTI
I'd started on 4000iu vitamin D3 daily but that wasn't enough and moving up to 5000iu daily and using sunlight in summer and a tanning light in winter made all the difference.
Magnesium is also helpful as that increases the actions of vitamin D and helps raise 25(OH)D levels faster.
Like Duffcooper I've not had a UTI for years now so do be aware you can beat UTI and you don't have to go the repeat antibiotics route.
It does help if you are taking antibiotics to use a PROBIOTIC between the antibiotic doses. The trouble with antibiotics is they kill of all your gut bacteria the good as well as the pathogens but it's the pathogens that tend to reestablish quicker so the more antibiotics you have to use the worse your gut flora become and the more prone you are to antibiotic resistant infections. Thats why using your own produce antimicrobial peptides is the best long term solution.