I was told I had a looping colon, and the doctor could not penetrate the colon to get a colonoscopy done. I then went for a Virtual Colonoscopy which was not conclusive if there was a polyp or residual feces after clean out. Now doctor wants to try to do a colonoscopy again, but if he cannot get in there I might have to have a resection of colon if polyp is suspected. How invasive is this resection of colon?