Hi and welcome to Healthcaremagic. Thank you for your query. I am Dr. Rommstein, I understand your concerns and I will try to help you as much as I can. No, I dont think this is relatd to Flagyl or any other medications and this is more a sign of uroinfection and this is common in your age and usually is manifested with pain during urination, fever and changes in urination frequency. Less commonly, this may be sign of liver disorders. Also, in case of uroinfection, blood traces may be present in urine which can have odour or colour change. Other common cause are urinary stones. Diagnosis is established by doing urine analysis and urinoculture and after this antibiotic treatment may be started if necessary. If there is negative urine analysis then you should do ultrasound of kidneys to check for stones. You should drink plenty of fluids and take raspberry tea or juice to promote urination. I hope I have answered you query. If you have any further questions you can contact us in every time. Kindly regards. Wish you a good health.