The damage and injury caused to the abs after c section isn't as bad as most people think because the incision used during a c section doesn't normally cut through the muscles, only the sheath covering the muscles (the aponeurosis) is affected, then the two sides of the muscles are pulled apart.
Training the abs after a c section is very important and there are a number of factors as to why you should start doing this at once following the birth. Firstly to help to pull in and realign the stomach muscles, without doing this, you run the risk of having a domed stomach for the rest of your life.
Secondly to strengthen and support the lower back and spine. The stomach muscles form a key part of what we fitness professionals call the core muscles. The job of the core muscles is basically to support the body so it can sustain a good posture and to protect and hold in the internal organs.
The third reason you need to exercise the abdominal muscles is to improve blood flow to the area. When muscles contract or do some work, they require a greater supply of oxygenated blood, it is this supply of blood which also contains the cells required for repair of the scar and surrounding areas. By regularly supplying a larger amount of blood to the scar the area will be able to repair much faster.
The chances are at first you won't be able to feel very much if anything at all whilst doing these stomach exercises, just keep doing them to the best of your abilities.
It is very important to only do a certain few pelvic tilting exercises that have been created for women who are recovering from c section and not to just start trying any type of the usual abdominal exercises, these are not appropriate at this time.