A Urinary Tract Infection (UTI) is an infection in any part of your urinary system — your kidneys, ureters, bladder, and urethra. Most infections involve the lower urinary tract — the bladder and the urethra. As compared to men women are at greater risk to get affected by UTI.  UTIs are a key reason we're often told to wipe from front to back after using the bathroom. That's because the urethra -- the tube that transports urine from the bladder to the outside of the body -- is located close to the anus. Bacteria from the large intestine, such as E. coli, are in the perfect position to escape the anus and invade the urethra. From there, they can travel up to the bladder, and if the infection isn't treated, continue on to infect the kidneys. Women may be especially prone to UTIs because they have shorter urethras, which allow bacteria quick access to the bladder. Having sex can introduce bacteria into the urinary tract, too