Hello dear Understand your concern Foul smells urine and back pain suggests possibility of urinary tract infection.(Kidney infection: can cause back pain due to inflammation and infection). I will treat this case as follows: First go for investigations like: urine routine, microscopic and culture, CBC, USG (to exclude stone). Urinary tract infections can be treated as below: Tablet septran plus nitrozolium, urine alklizer like potassium citrate or syrup Cidal, Tablet diclofenac plus paracetamol. Then antibiotic should be given according to culture report, Drink plenty of waters (2.5-3 liter), drink juice of cranberry, always empty the bladder completely to reinfection, maintain hygiene before and after urination and sex. Also exclude the diabetes by fasting blood sugar analysis. Hope this may help you Best regards Dr. Sagar