Urinary tract infections (UTIs) occur when bacteria enter the urinary tract through the urethra and begin to spread in the bladder. The urinary system is designed to keep out bacteria, but sometimes the defenses fail, and bacteria take hold and grow into a full-blown infection in the urinary tract. The most common UTIs occur mainly in women and affect the bladder and urethra. The most common cause of UTIs is Escherichia coli (E. coli), a type of bacteria commonly found in the gastrointestinal (GI) tract. However, sometimes other bacteria can cause UTIs. Having sex can also lead to a bladder infection, but you dont have to be sexually active to develop one. Women are at greater risk of developing a UTI than men because the female urethra is shorter than the male urethra, and it is closer to the anus, making it easier for bacteria around the anus to enter the urethra and cause an infection. Other factors that can increase the risk of UTIs include:

• A previous UTI
• Changes in the bacteria that live inside the vagina, or vaginal flora. For example, menopause or the use of spermicides can cause these bacterial changes.
• Pregnancy
• Age (older adults and young children are more likely to get UTIs)
• Structural problems in the urinary tract, such as an enlarged prostate
• Poor hygiene, for example, in children who are potty-training

Diaphragms can increase bacteria growth, while unlubricated condoms and spermicides can irritate the urinary tract, making UTI symptoms more likely.