It is most commonly seen after urethral injuries, for example due to the careless introduction of a urinary catheter for any reason. Because the urethra is very narrow in one place, the flow of urine is difficult and serious changes in the bladder can occur, sometimes making it completely impossible to urinate. If the narrowed part of the urethra is short, the problem is successfully solved by surgery through the urethra, in which the narrowed part is dissected, widened and thus allows normal flow of urine. The operation lasts briefly (10-30 minutes), the patient goes home the same day or the next day and carries the catheter for a few more days.