Sneezing or Coughing After Tummy Tuck

A large percentage of the pressure that’s necessary for a
forceful cough or sneeze comes from contraction of the abdominal muscles.
Unfortunately, in the post-operative period coughing and sneezing are often associated
with significant pain.In the
post-operative period the abdominal muscle closure has regained most of its
pre-operative strength in about six weeks. Despite this coughing can still
result in significant pain because scarring, swelling and inflammation from the
healing process.It
would be unusual for coughing and sneezing to disrupt the abdominal muscle
closure six weeks following surgery. However, pain associated with coughing and
sneezing may last for three to six months following surgery.For
this reason, we generally recommend that patients splint their abdominal
muscles whenever they’re sneezing or coughing. When this approach is utilized,
pain is minimized and patients are more comfortable in the post-operative
period.

Hi there-
After 6 weeks, your wounds (both on the surface and at the level of your muscle repair) should be very strong, and the risk of inadvertently tearing your stitches and damaging your outcome should be very low. This accounts for the safety of releasing patients from most activity restrictions at 6 weeks.
The pain you feel when you cough or sneeze (as well as with certain bending or twisting movements) is most likely due to stretching of the scar tissue your body has formed under the skin that occurs with these movements.
Unlike healthy skin and tissues, scar tissue is firm and inflexible, so any movement that requires it to "give" a little will cause you a bit of pain until the scar has reached a level of maturity, which takes months...
You can help this along by performing slow stretching exercises, as in yoga. In any case, the sensations usually resolve on their own after about 6 months, so it shouldn't be a long term problem for you.