There are many things that can cause female burning...

1) acidic urine may burn... high Vit C intake is one cause. But acidic urine may be from lifestyle as well (food)

2) over use and improper rinsing of soap from the female genitalia may inflame membranes and cause discomfort. Soap residue from washing clothing, or use of fabric softeners can do this too. Double rinse clothing if in doubt and don't use softeners with underwear.

3) Wearing very tight clothing, or thongs. (thongs have been implicated in bladder infections and vaginal infections in women).

4) Yeast infections irritate also. There is a test now (not cheap) in drugstores that you can use to screen yourself. Other than yeast there are other organisms that can be there too. Yeast can follow antibiotic treatments in women as well.

Real bladder infections are very painful. Irritations are more common and often mistaken for them. So there are things you can do-- be a detective.