All of my mainline suture lines dehysse (pop open) post op...from 7 days to 3 months post op I can pop.
Then I go through the cleaning/packing/waiting until it closes. But all of that is just skin deep most of the time. It is not the muscle that holds your abdomen together...if it were the muscle then they would suture it closed.
So once the skin is granulated in or closed, it is closed.
Take it easy at first, not because of the fact that it popped open but because you just had major abdominal surgery.
Take it slow, do half of what you would normally do and work your way up.
Stop if there is any major pain.
Sharon