Which method will they be using ultrasound or cystoscopy for checking my bladder after urine sample turned out clean?

Here is...: Bladder ultrasound scanner is good for daily use to check if bladder empties well after voiding. Incomplete emptying suggestes significant bladder weakness resulting from muscle or nerve damage. Cystoscopy is usually not necessary although at times useful to confirm the bladder changes from its outlet blockage commonly by prostate enlargement or... So, how far will the evaluation go? Ask urologist.