Thank you for your post. Whenever there is a potential space in your body, your body tends to fill that space with serous fluid (the yellow type of fluid that also comes out of a 'weeping wound'. This is similar to when you get a blister: the layers of skin separate and fluid is deposited in to the space. In a tummy tuck, the space is in between the skin/fat layer and the muscle layer. Most surgeons will place a drain to remove this fluid while your body is secreting it until the fat layer grows back together with the muscle layer. At that point, no more fluid is secreted into the area, because there is no more space for fluid. The length of time that this takes varies from patient to patient. Some patients heal much faster, thus the layers seal together much faster. Also, the more twisting motion you have in your belly area, the slower the two layers grow back together because they are moving in relation to each other. The fluid coming through the drain can be initially dark red, and eventually clears to pink then yellow. This is because it takes just a little bit of blood to make the fluid dark red. Also, initially, there can be a large amount of fluid (few hundred cc's in the first day is not out of the range of normal) and this should slow down substantially over next few days. Once the fluid slows down to the amount that your surgeon is comfortable with (usually 25-50 cc in 24 hours) then they will be pulled. There is minimal discomfort in pulling the drain in most patients.
More recently, 'drain free' surgery has become more popular. Fat layer is sutured down to the muscle layer starting at the ribs and progressively down to the lower incision. This makes the space for the fluid to collect much smaller, and in many patients can have surgery without drains. However, I have seen multiple patients come from other surgeons because they developed a seroma despite the suturing of the tissue. This is not the surgeon's fault, but some patients just do not heal fast enough or put out too much fluid for the body to absorb.
Pablo Prichard, MD