The entrance of bacteria into the urethra is not the only way a urinary tract infection can start, and plenty of people who are not sexually active get UTIs. Sometimes, a physical condition may be the cause. When it is, antibiotic treatment alone won't resolve it. Your doctor may refer you to a urologist (a specialist in the urinary tract) if he or she isn't sure of the precise cause of your symptoms.

Kidney Stones

UTIs can result from physical blockage. The most common obstacles are urinary stones (calculi)—usually called kidney stones—which send approximately 1 of every 1,000 adults to the hospital in the United States each year. Consisting mostly of calcium, and therefore as hard as a rock, these stones can be any size from tiny to large enough to fill an entire kidney.

Kidney stones travel with the urine and can be found anywhere in the urinary system. They may be painless or excruciating, depending on their size, their location, and whether they are blocking the passage of urine. If a stone becomes lodged in the thin, sensitive ureter, pain is notoriously great. X-rays will show their location. You will need surgery or lithotripsy, in which the stone is "blown up" with ultrasound, if the stone is in a particularly painful or dangerous place and won't pass through the system of its own accord.

An Inviting Nook for Bacterial Growth From its position immediately overhead, the bladder can push into the vaginal area when surgery, menopause, or multiple deliveries weaken the vaginal wall. The resulting pocket, called a cystocele, allows urine to collect, providing especially hospitable conditions for invading microorganisms.

Cystocele

Another cause of a UTI is a cystocele. When the vaginal wall next to the bladder has become weakened for any reason, the bladder can protrude directly into the vagina, holding back small pools of urine. Such tissue weakening is common after several vaginal deliveries, menopause, or gynecologic surgery. Cystoceles may require surgery themselves. Diverticula

Diverticula are crevices (abscesses) that develop on the inside wall of the urethra. If several of these small pockets merge to form a larger one, urinary debris can accumulate in it. When diverticula become swollen or inflamed, urine may not drain well, leading to chronic infection. Surgery may be required. Suspect diverticula if you feel burning on urination between bladder infections.

Diverticula: A Long-Term Source of Trouble If a pouch develops at a weak point in the wall of a tube such as the urethra, it's called a "diverticulum." A trap for all sorts of debris, it can become a permanent reservoir of chronic infection. Diverticula in the urethra can become inflamed, causing discomfort whenever you urinate. Diverticula cng abdominal infection.

Urethral Stenosis

A narrowing of the urethra, called urethral stenosis, can be present at birth or result from a number of conditions or activities. These include having had a UTI in childhood; infection of the vagina or vulva; previous infection, such as gonorrhea; a sudden increase in your sex life; childbirth; catheterization after surgery; the physical changes of pregnancy; and changes related to a deficiency of estrogen during and after menopause.