Urinary tract infection is caused by bacteria entering the urethra and bladder. Cystitis is the most common form of urinary tract infection. Then you may need to urinate often and it may burn. The trouble usually subsides after a few days.
Urinary tract infection is a fairly common disease in children. It is caused by bacteria entering the urethra and bladder. When the bacteria stop there it is called bladder catarrh. The bacteria spread to the kidneys and the renal pelvis is called renal pelvic inflammation.