Recently had a UTI, took series of antibiotics. Finished medication two weeks ago. Three days ago, symptoms returned, urgent need to urinate with slight pain. Today sharp pains in waist area left side. Pain from front & back with spasms..

You really need to go back to your doctor. There's absolutely no way that anyone can give you an accurate diagnosis online. We'd need your urine, your blood, and possibly more. Since we don't have access to that, we can only guess. Guesses aren't answers, and they won't help you.

Please see your doctor.