Your tummy will feel different. You should notice that you are no longer in the kind of pain you have long experienced. When you stand, support your scar with either a little pillow or your hand, everything will feel as though it's 'falling down' inside, but this is only everything adjusting inside and being accommodated into the new space.
By the second or third day, most patients are up walking and are expected to go to the toilet on their own, and can expect to see the surgeon. You will also be given pain relief, the hospital staff should give you any information you need and a nurse should discuss with you the correct way to move and when to resume your normal activities etc., before you are allowed to go home. (Remember to use a wheelchair to get to the car, since you will feel very unsteady and probably quite lightheaded!)