I have on & off left sided pain high up as belly button & lower back left sided pain since feb. not constipated, trace blood in a urine sample 2 weeks ago but dr did not think it needed looked into what could this be?

I would like to see the results of a urinalysis with a microscopic examination of the urine sediment. If this demonstrates microscopic hematuria, concern for left kidney pathology, such as stones,cysts,growths, would be raised& an ultrasound,at the very least, should be ordered. Descending colon pathology is unlikely in the absence of bowel symptoms. The ultrasound can check for pelvic pathology.