Subcision post op can be painful and yes, there is often bruising and swelling. It really depends on who does it, what kind of needle they use, what method they use and how the individual personally responds to it. It is definitely, in my opinion, one of the most effective treatments for rolling, depressed acne scars. Post op care may include application of ice and use of anti-inflammatory to reduce swelling, and use of antibiotics to reduce risk of infection. Also, look into the subcision/suction method...results improve with suctioning after treatment. How long the patient remains bruised/swollen depends on how aggressive the doctor was with the treatment. I suppose it also depends on where the scar being treated is.