To Whom This May Concern, I Have The Following Medical

To Whom This May Concern,
I have the following medical problems:
* gastric bypass in 1998 with several fistula repairs
* osteoporosis
* back surgery In 2006, multiple leg surgeries
* possible going through menopause
So my question is with all these medical problems I have had several urine tests to test to see if the oxycodone is in my system and I have had tests saying it isn't in my system. With all my medical problems above affect the tests. I've done a little research but wanted to ask directly too. Thanks in advance for answering my question. Barb