Sorry this is a bit late (after you've had your c/s), but I experienced this too after my c/s. The OB and the physio said, as above, that it was air trapped in the abdominal cavity during surgery and that it would eventually be absorbed by the body. It was excruciating!! A heat pack helped, as did lying down flat until the pain abated. I had it intermittently for 2 days I think, but didn't feel the pain all the time, thank goodness.