It is not surprising that cystitis is common. The urethra, which is the outlet from the bladder, is so very close to a part of the anatomy where a host of organisms are to be found.
The bowel is like a zoo of microbes but it is quite capable of defending itself and the whole of the human body against the effects of the germs.
Unfortunately, it is only too easy for these organisms to reach the urethra and to spread upwards to the bladder and, under certain circumstances, even further to the kidneys.
In the bladder they cause intense irritation. But fortunately there are a number of antibiotics which will generally clear up the infection, especially if taken early enough.
Many articles taken from 'A word with the doctor', by Dr. John Windsor.