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Why can acute cystitis cause burning pain during and after urination?

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The most common cause of urinary tract infection is invasion into the urethra of Escherichia coli, a type of bacterium that normally inhabits the bowel. — urinary tract infection The most common cause of urinary tract infection is invasion into the urethra of *Escherichia coli*, a type of bacterium that normally inhabits the bowel.

In cases of acute cystitis, the burning pain experienced during and immediately after urination is primarily caused by the inflammation of the urinary bladder lining.1

When a bacterial infection occurs, the mucous membrane of the bladder becomes swollen, red, and prone to bleeding. This inflammatory process can lead to the development of small ulcers, the shedding of the surface layer of the bladder wall, and the formation of abscesses. Because the bladder is highly sensitive, these physical changes and the resulting irritation cause significant discomfort and pain when urine passes through the inflamed tissues.12