Did torn tummy tuck stitches cause a bulge?

I'm sorry to hear about the complication you have experienced after tummy tuck surgery. Hopefully you are working with a board-certified plastic surgeon. Depending on whether he used a single layer of “running” or “interrupted” sutures he will be able to re approximate the abdominal wall muscles that have apparently separated.

 In my practice, the  “repair” of abdominal wall diastasis  is done in 2 layers.It won't hurt to express  your concerns in a constructive fashion.

 Best wishes.

   One running suture if broken would not produce a tiny area of recurrence.  This is more likely one stitch among many that was compromised.  Realize that this compromise was probably not the result of technical error.   I see about 2 patients in 100 who have such weak fascia that stitches tear through the fascia as they are placed.  Very poor fascia may not be able to sustain the repair.

having an abdominal wall problem is not an unusual occurence.  there are many acceptable ways to correct this..  relax and take it easy postop so it has a good chance to heal the way you want it to