Is a Vertical Incision Required for Repair of Diastasis Recti with Umbilical Hernia?

It is not necessary to have a vertical scar to repair your umbilical hernia.

If you undergo a tummy tuck to remove extra skin, the incision will be horizontal.  Most plastic surgeons will repair the umbilical hernia at the time of the tummy tuck.

You may be a candidate for a limited incision tummy tuck. 

From the appearance of your abdomen, it appears that a vertical is not the only solution, Therefore, I would get other opinions prior to proceeding.