is there any swelling at the site? any scans recently? Any medical illness ?
any weight-loss or loss of appetite?
Some pathologies which can produce such symptoms are inflamed liver or gall bladder or a hernia at the site.Muscular problems can also present like this as you experience it when you bend.The best option would be do an ultrasound scan of the abdomen to diagnose any obvious causes like mentioned above.If these tests are negative then probably muscular cause could be culprit.You can start on painkillers and anti -inflammatory drugs and hot compresses if it turns out to be a sore muscle.
Adding an antacid would also recommended as rarely acidity can cause abdominal pain.
Better to have a routine colonoscopy as you have a history of polyps.
Sometimes obstruction to the bowel will cause it to contract more powerfully than normal to overcome that obstruction and cause such twisting pains.It could be anything from the adhesions to mass in the bowel.
This twisting pain can be because of intestinal cramps.
But it is more after eating food or during bowel movements.Bending and straining has less chances of inducing intestinal cramps, unless there is an inflamed organ in the abdomen which gets compressed or irritated on bending or straining.
Scan and the colonoscopy would almost in every case detect any abnormality in the bowel.