Hi, Think the most important point here is that we should not assume anything. There are several possible causes of the sentence what you re experiencing which certainly includes the kidney stone what you mentioned. Also sometimes if there is a mild degree of inflammation of the prostate gland it can cause episodic changes in the urine and some discoloration or blood in the urine. It sounds like you have had quite a federal work up performed so far. I still think that a periodic examination and follow up with a urologist with possible interval imaging studies including a CAT scan which can be done on a yearly basis is a reasonable approach. In addition, it would be important to also check your blood count to make sure there is no disturbance or development of anemia. I doubt there is anything worrisome going on I just want to make sure you have a thorough workup in the event that there is something that has not really declared itself just yet. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Ivan R. Rommstein, General Surgeon