One theory, from a nurse practitioner I spoke with:
Bacteria love an alkaline environment. So when you eat super-alkalizing foods and create an alkaline environment in your urinary tract/bladder, that can speed up the growth of bacteria if they're already in your system or you've been exposed to them.
I've never heard of infections as a detox symptom -- they're really just opportunistic bugs that like an alkaline environment -- but regardless of how they are classified, you want to treat this.
Natural remedies include:
(1) Look for some tables of acid/alkaline foods and try to find some raw-veg-friendly foods that will push you from super-alkaline (I once tested with a pH of 8.5 = way too high!) to slightly-alkaline (I've heard the optimum is 7.3-7.5 or around there). Just a slight acidification can make a difference.
(2) Pure cranberry juice (acidifying to the urinary tract). Personally I wouldn't worry about getting some organic pasteurized 100% cranberry juice, think of it as medicine and not as food, but that's just me.
(3) One of the best anti-infection herbs for "down there" is uva ursi, in extract capsules or tincture. Uva ursi was often used for treatment of urinary tract/bladder infections before the invention of sulfa drugs and other modern antibiotics.
I've had to go on antibiotics in the past when such infections didn't go away naturally. Nothing wrong with that -- after all, bladder infections can spread to the kidneys (and that's REALLY not fun). Just restore your good flora with probiotics after an antibiotic round of treatment, if you need to go the conventional route.