According to the NHS there's no evidence that drinking lots of water is an effective treatment.
But they recommend it anyway?
The fact that drinking loads of water really helps flush out your bladder and makes you feel better doesn't count as 'evidence'.
'Evidence' means enormous cohort studies and double blinding and boring statistical analysis programmes. Nobody's funding trials into tap water.
This grumpy post was brought to you by Boxing Day Headache Lurgies inc.
As one who seldom CBA to read or acquire much evidence, and also one who suffered multiple UTIs in the past, I adopted my own strategy (mostly before Evidence Based Medicine became trendy).
Assuming there are times and places where frequent loo trips are a right PITA but others where it's OK, this is what I did.
Find comfortable place close to loo and drinking water source.
Get pint glass and fill it with water or diet squash choose something palatable.
Drink it all.
Refill glass after your next loo visit
Repeat until you have had 4-6 pints in 3-4 hours.
Then drink generously but 'normally'.
My reasoning:
E.Coli bugs (a common cause of UTIs) can double in number every 20 minutes.
You can wash their numbers down by intense dilution to a level your body can tackle them.
Assume one million bugs per millilitre, a bladder capacity of 300ml and a residual bladder volume of 30ml.
Do the 'math', try to empty your bladder fully and get better soon!
Just pushing fluids blandly may not work because it is too non-specific.
Drinking lots if not peeing can be dangerous.