Thanks for contacting healthcare magic. You are Mention mention that you have problem of urinary tract infection. You are already taking antibiotics. Sometime infection may spread to kidney that can lead to back pain. Do a urine culture test than start appropriate antibiotics course under doctor s suggestion. Complete a course of antibiotics. Drink more water per day.. So urine can dilute and flush out a bacteria. Avoid spicy foods, caffeine, tea and alcohol drinking. Take craneberry juice helpful in uti. Avoid tight clothes. Maintain proper hygiene. Frequent urination. After taking this much care still symptoms are present than consent a physician for further diagnosis. I hope my guidance helpful to you.. Take care. Thank you.