Will sneezing cause damage to internal sutures?

Thank you for your question and congratulations on having undergone the tummy tuck procedure.
 
Generally speaking the plication of the abdominal wall is very secure and it would take significant force / trauma to disrupt this repair.  Generally speaking, a sneeze, cough and/or straining will not generate enough force to harm the repair.
 If you remain concerned, I would suggest that you visit with your surgeon for an examination so that he/she can (most likely) put your mind at ease.
Best wishes for an outcome that you will be very pleased with.

Thank you for your question. It is always best to try to brace yourself for things like this, but they are unlikely to cause significant problems. If you did not have onset of pain or swelling after the incident, things are probably fine. If concerned, you should follow up with your surgeon.Hope this helps!

but its unlikely.  If it did happen, you usually feel a popping sensation as your sutures fail.  And if you're really concerned, you should see your surgeon for an evaluation.  At 5 weeks post-op, I would not expect this to happen as your tissue is already healing together and adding additional strength to your repair.