Day three after explant surgery and I am experiencing a very sore stomach, mid-section, sides and back. Any suggestions?

Thank you for your question.  Explant surgery involves re-using your former breast incision to gain access to remove your implants.  If no other surgery, like a breast lift, is planned, then operative time and recovery time is fairly minimal.  When you are on the operating room table, there are "seat belts" placed loosely around you in order to protect you during surgery, but you are definitely not inverted. I would recommend you see your surgeon to allow for an in-person examination to see what may be causing your symptoms.  

Everyone experiences pain, bloating and swelling after surgery.  This will improve with time.  In the meantime get off the narcotic pain pills, this will help considerably.

Bloating a few days after surgery is may be related to "slow movement" of your bowels from a combination of anesthesia from the surgery and especially pain medication.  Narcotic pain medication can slow down the bowels and cause bloating.  The pain in your stomach could be related to the bloating.  The harness marks might be from the straps that are always placed over the patient during surgery to keep them secure on the operating room table.  They do not invert you to do the surgery.  Usually those straps are loose enough to prevent harm to the body, but it's possible they were too tight.  You would need to be examined by your doctor to check that.