Shoulder pain after CS is not uncommon. It is caused by a number of things air in the body as monnie said but a more common cause is known as referred pain. This is where one part of your body is injured but you feel the pain somewhere else. One example of this would be a heart attack where it is very common to feel pain in your arm. During a CS your internal organs do get bashed around a little and this bashing of your organs is a common cause of referred pain in your shoulder. The pain usually goes away within a few weeks.