Hello dear Warm welcome to Healthcaremagic.com I have evaluated your query in details . * The frequent urination is due to urinary tract infection . Needs plenty of liquids , cranberry sachet once daily in a glass of drinking water ; later if needed urine microscopy report and antibiotics . * The pain over back at last rib seems from renal calculus or gravels , must get an ultrasound examination done for the final diagnosis and further management in accordance with that . Wishing you fine recovery . Feel free to ask any further queries . Regards .