Thanks for posting your query.
Presence of urinary tract infection
with low backache
may be due to some sort of obstruction in urinary tract system.
You should consult wit internal medicine specialist/ general surgeon/ urologist
and should go for thorough check up.
You should also go for ultrasound
imaging/ x ray KUB region, urine routine microscopy and urine culture & sensitivity test.
You should first go for above prescribed investigation and continue antibiotics as prescribed by your treating doctor.
You should also take urine alkalizer for eradicating urine infection.
Dr. Mayank Bhargava