A seroma is a collection of non-bloody fluid that can collect after any surgical procedure. Because of the large area of dissection involved in a tummy tuck, this operation, has a higher risk and therefore most plastic surgeons use drains to decrease the chance of seromas. Blisters can be caused my a variety of things. I have stopped using tape and steri-strips on the skin with tummy tuck as I think they had a high rate of causing blisters.