Thank you for the prompt reply.
It sounds like she is experiencing inflammation of the bladder but the cause of the inflammation can be due to various things. In an older cat, a bacterial infection is more likely than in a younger cat. Bladder stones are another possible cause, but in some cases, we will see inflammation due to unknown cause occurring and this condition is referred to as idiopathic cystitis. In all of the cases, if there is enough inflammation that she is bleeding and producing blood clots, she has to be fairly uncomfortable. For that reason, even though these are not usually life threatening cases, I would recommend veterinary intervention sooner versus later so that the diagnosis can be made and medications to help make her more comfortable prescribed. Besides a thorough physical exam, a urinalysis and possibly even an abdominal xray should be performed to help diagnose.
In the meantime, try to encourage increased water intake as best you can. You can add warm water or broth to her food to make it is soupy as she will allow. This will help to keep her urine more dilute and will help to flush out her urinary system.
I hope this is helpful. Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please reply so I can clarify for you.
My posted replies are for general education only and not meant as a diagnosis. Only after a thorough veterinary examination can a diagnosis for your pet be made and specific treatments be advised or medications be prescribed.