Because the female’s urethra is very short and its external orifice is close to the anal opening, inproper toilet habits (wiping back to front after defecation) can easily carry fecal bacteria into the urethra. Actually, most urinary tract infections occur in sexually active women, because intercourse drives bacteria from the vagina and external genital region toward the bladder. The use of spermicide kills helpful bacteria, allowing infection fecal bacteria to colonize the vagina.
The urethral mucosa is continuous with that of the rest of the urinary tract, and an inflammation of the urethra (urethritis) can ascend the tract to cause bladder inflammation (cystitis) or even renal inflammations (pyelitis or pyelonephritis). Symptoms of urinary tract infection include dysuria (painful urination), urinary urgency and frequency, fever and sometimes cloudy or blood-tinged urine. When the kidneys are involved, back pain and a severe headache often occur. Most urinary tract infections are easily cured by antibiotics.