Hi Marina: Here is some info I got off the web. I know some in my family used to get them often and were told to drink plenty of water and cranberry juice.
UTIs are more rare in boys and young men. In adult women, though, the rate of UTIs gradually increases with age. Scientists are not sure why women have more urinary infections than men. One factor may be that a woman's urethra is short, allowing bacteria quick access to the bladder. Also, a woman's urethral opening is near sources of bacteria from the anus and vagina. For many women, sexual intercourse seems to trigger an infection, although the reasons for this linkage are unclear.
According to several studies, women who use a diaphragm are more likely to develop a UTI than women who use other forms of birth control. Recently, researchers found that women whose partners use a condom with spermicidal foam also tend to have growth of E. coli bacteria in the vagina.
People with diabetes have a higher risk of a UTI because of changes in the immune system. Any other disorder that suppresses the immune system raises the risk of a urinary infection.
Doctors suggest some additional steps that a woman can take on her own to avoid an infection:
Drink plenty of water every day.
Urinate when you feel the need; don't resist the urge to urinate.
Wipe from front to back to prevent bacteria around the anus from entering the vagina or urethra.
Take showers instead of tub baths.
Cleanse the genital area before sexual intercourse.
Avoid using feminine hygiene sprays and scented douches, which may irritate the urethra.
Some doctors suggest drinking cranberry juice.
Hope this helps!