hi, most common cause of bleeding in urine is enlarged prostate
gland, once urine infection and stone disease are ruled out. It is important to evaluate any case of blood in urine as cancer of bladder or prostate can also be a cause. In your father's case, Cystoscopy
and clot removal were done so we assume that after clot removal, the doctor had re-checked the bladder to see for any bladder tumor
and it was not present. Repeated blood in urine becomes one of the indications for surgery for prostate gland. during surgery, enlarged portion of gland will be removed endoscopically and sent for biopsy
. further treatment depends on biopsy report (benign or cancerous). get a urologist
consult. good luck.