Completed antibiotic course for uti infection; symptoms returned after a day, urgency, burning, discomfort. symptoms were completely gone save for urgency just 12 hours ago. whats up?

Probably your UTI was caused by a bacteria resistant to the antibiotic you took. Check back with the clinic or doctor treating you. Good luck.

Two possibilities. The duration of the treatment was not long enough or a return of infection . Good idea to get a urine culture and Sensitivity and in the meantime drink plenty of water and some cranberry juice. Good luck