Diastasis Recti Repair and Umbilical Hernia Surgery Without Tummy Tuck?

Thanks for inquiry, but without a picture it hard for me to comment thouroughly.  If your surgeon is suggesting some sort of laproscopic-minimally invasive scar technique and you do not have much loose skin-that could be an appropriate treatment.  I will tell you that often when you plicate the muscle without altering the overlying skin-you can have areas where the skin gathers.  Get another opinion in your area as well.

First of all, if you are considering more pregnancies, you may want to consider only having the hernia repaired because of the likelihood of recurrence of the diastasis. 

Without photos and more history, whether or not the suggested approach is a good one is hard to answer. If the diastasis is wide, suturing the muscles together can cause a "gathering" and vertical wrinkling of the abdominal skin. This may be somewhat unpredicatable. 

All the best.