dear user about your question i would like to tell you that these symptoms refer to having urinary tract infection or small renal stones and we should investigate that first you should do ultrasound scan of abdomen to see if there is any small stones that may be the main cause of that pain you have second step you need to do urine culture as primary investigative test of bacterial infection as in this case you should have antibiotics for treatment ...althaugh you took bactrum but it may have no effect as there is bacteria may resist it and urine culture and antibiotic sensitivity test will detect simply the way of treatment and selection of the approbriate antibiotic that will give best results with bacteria detected........discuss with your doctor to do urine culture and antibiotic sensitivity test as it will help alot.......you should drink alot of fluids and drink water alot of times to help get away these small stones and dilute it..........wish you healthy life