From your description and the straining feeling I would bet that you have an inguinal hernia. Not something to trifle with. It is a weakness in the abdominal wall that allows the internal organs to protrude through the wall. Yes you can push them back in but they will come back out. I had a rather minor one myself some years ago. I would urge you to see a doctor and let him determine the severity of your situation. I do not think this is PCa.
PSA 21.5 (first and only test resulted from follow up visit to emergency room for kidney stone. first time for kidney stone too)
Gleason 4 + 3
DRE palpable tumor on left side
100% of 12 cores positive for PCa range 35% to 85%
Bone scan clear
Chest x ray clear
CT scan shows potential lymph node involvement in pelvic region
Started Casodex on May 2 and stopped on June 1, 2008
Lupron injection on May 15 and every four months for next two years
PSA test on July 14, 08 after 8 weeks hormone .82
Started IMRT/IGRT on July 10, 2008. 45 treatments scheduled
First 25 to be full pelvic for a total dose of 45 Gray to lymph nodes.
Last 20 to prostate only. Total dose to prostate 81 Gray.
Completed IMRT/IGRT 09/11/08.
Second Lupron shot 09/11/08
Next PSA test by oncologist 03/09