Hernia or Rectus Diastasis?
A clinical exam can help determine if you have a hernia or a rectus diastasis. If there is any question, a CT scan can also be done to know for sure, however this is not always necessary. A severe rectus diastasis can be seen after pregnancy, typically if there was a large baby or if there were multiple babies stretching your tissues. You and your plastic surgeon can discuss the repair during tummy tuck and the expected outcomes.
Tummy Tuck for Diastasis recti with or without hernia
Based on these pictures, there is severe weakness + severe stretching of the abdominal wall muscles. The weakness can be improved with exercise but this amount of stretching needs surgery for the whole abdominal wall. There is a hint of a hernia at the umbilicus which is common when this much weakness and stretching exists. Generally speaking, the stronger the muscles the better the result will be. So do your homework before you have your tummy tuck so you can get the best looking result.
Based on your photos which is not the most accurate way to determine a 100%, you do not seem to have a hernia. It looks more a diastasis of the muscle as well as the combination with intra abdominal fat.
The Tummy Tuck and specially muscle repair will be a great help to bring your intestines back inside of the cavity and achieve a flatter abdomen.
You have to be very careful because your lungs and respiratory muscles may have issues to breath because of the volume that will be brought into the cavity. So you have to start doing cardio, wear a compression garment in order to get a costumed to be tight again and pulmonary therapy before surgery.
Be encouraged. You will be loving your flat abdomen and tapered waist.