When the doc says blood and pus in urine specimen can be caused by collection what does he mean?

Blood and pus in a urine specimen can sometimes be caused by contamination during the collection process rather than representing a true infection. This can happen if the container used for collecting the urine is not sterile or if the person providing the sample does not clean the genital area properly before collection. In such cases, the presence of blood and pus may not be indicative of an underlying medical condition and can be ruled out by repeating the urine test with proper collection techniques.