In most cases, yes. I (just me,,,has no relevance to actual statictics)have not known of a UTI to date that was not treated with antibiotics. The reason is UTIs are almost always due to bacterial infection. The proximity of the rectal area to the urethra is commonly the culprit. Bacteria that exists in the rectal area are not compatible with the urinary system. Cases of viral UTIs exist but are not as common. Check out WebMD for more info.

Not to take away from the previous answer, but being a constant sufferer of UTI's there are a couple of things that help. The first is drinking lots of cranberry juice and water; the cranberry juice contains a natural antibiotic to help fight the UTI, water keeps you from getting dehydrated. Another thing that helps is yogurt-WITH ACTIVE CULTURES-either eaten several times a day and/or applied directly to one's genital area. When using yogurt get the unflavored kind that will say "with active cultures" on the container. The active cultures that it contains are a good form of bacteria, this will help your body fight the "bad" bacteria. When applying yogurt to the genitals, leave on for 15 minutes then rinse off with warm water. The best time to do this is prior to bathing or showering. One thing that can cause UTI's in addition to the first answer is douching too much or too frequently. Douching removes ALL bacteria from your body-the good and the bad kinds, leaving your urinary tract system unable to defend itself from infection. If you have a tendency to get frequent UTI's (more than twice a year), definitely mention this to your doctor, they may decide to put you on a constant course of low-dosage antibiotics. But beware that your body will build up a resistance after a while and they won't work as well.

My doctor gave me a sulfa drug and it worked just fine every time it recurred.