Diastasis recti sutures coming undone? Can the sutures come undone years later, leaving me with a bulging belly again?

Initially, the sutures serve to hold the muscles in place. However, over time they will scar in place and at that point they are no longer necessary. While many surgeons use permanent sutures, some use absorbable sutures which is a testament to the temporary nature of the need for sutures to hold the plication.In the early post-op period, the repair can fail. There is also always a chance for late recurrence (very low), especially in the setting of pregnancy or weight gain. For this reason, many surgeons will do a 2 layer repair with permanent sutures.As always, discuss your concerns with a board certified plastic surgeon (ABPS).

Dear j.elizondo,
the main role of sutures is to hold the 2 sides together until they heal together with a scar. After a few months the sutures should be resorbed by the body and the scar tissue will hold the muscles together. I suggest you to consult with a plastic surgeon if you suspect anything. 
Daniel Barrett, MD, MHA, MS 
Certified, American Board of Plastic Surgery 
Member, Am. Society of Plastic Surgery

While it is possible for sutures to fail early on in your recovery (and I have seen that happen at least one time in a colleagues patient), it is exceedingly unlikely later.  After a few months your body should heal and the two rectus abdominis muscles should scar together - negating the need for sutures to be in place any longer.  If you are having trouble years later I suppose it could be that you've developed some kind of hernia, but realistically I would guess it simply has more to do with a need for abdominal exercise and toning.

If your tummy was flat after surgery and remained so for some time, then it is very unlikely that a recurrent belly bulge years later is due to the diastasis repair sutures coming undone.  Initially, during the healing phase, the muscle plication sutures are critical in holding the rectus muscle together.  However, the resulting scar tissue is what ultimately holds everything in place and provides strength.  It is possible for the muscle itself to relax and stretch over time if the muscles are weak -- age, weight gain, disuse, previous surgery, subsequent surgery, large-volume meals, etc. are some of the factors that may have a significant impact on later development of abdominal bulging. Of course, an abdominal hernia must also always be considered if there is bulging.
In the absence of a hernia, weight loss (if there is excess intra-abdominal fat) and abdominal exercises may correct the bulging.  If your abdomen does not respond, you may well need a redo tummy tuck with additional muscle plication to restore a flatter tummy.  

Thank you for your question. After several years it is unlikely sutures hold your muscle anymore. It may be hernia or laxity again other. Please see a PS for evaluation.