I have had 3 uti's in three months. i was given bactrim (sulfamethoxazole and trimethoprim) for 5 days and last time for 7 days. hopefully doesn't come back. have any tips?

Resistant bacteria?: First, confirm the diagnosis. Second, you may be infected with a bacteria not highly responsive to Bactrim; if 5 days didn't work, 7 days also is questionable. Ask your doctor about a urine culture to determine exact bacteria causing it and which antibiotics will work best -- usually a quinolone (e.g. ciprofloxacin) if bactrim (sulfamethoxazole and trimethoprim) doesn't do it.