Urinary tract infection (UTI) is one of the most common bacterial infections affecting children. The disease is most often caused by Escherichia coli – a bacterium naturally living in the intestines, which is often transferred from the area of the anus to the urethra as a result of improper hygiene. Then there is inflammation of the bladder and urethra. In the treatment of cystitis in children, medicines prescribed by a doctor (including antibiotics), over-the-counter preparations (e.g. based on cranberries) or herbs for brewing to prepare sit-ups (e.g. chamomile) are used.