Can I use Mucinex DM for cough after Tummy Tuck?

You should check with your surgeon regarding the medication.  He/she will most like say it is ok.  Make sure you are getting up and moving around and 3-4 times a day are making yourself take deep breaths to help keep your lungs expanded and clear.  If you need to cough, try and hold a pillow very firmly against your abdomen.  You will be able to splint the muscles and reduce some of the discomfort.