Liposuction involves the infusion of dilute local anesthetic solution into the areas where fat removal is planned, usually in a volume at least equal to or greater than the volume of fat removal anticipated from that same area. This solution helps to make the procedure less painful, and to diminish the potential bleeding.
Once the fat has been suctioned, there is usually some residual dilute local anesthetic solution and a small amount of blood left in the tissues. This blood-tinged fluid leaks out from the liposuction incisions for the first 48 hours or so, after the procedure, like water being wrung out of a sponge. This is beneficial, since it is desirable not to have a collection of fluid (seroma) in the space where the fat was removed. For this reason, most surgeons use compression garments to limit the ability of fluid to accumulate, and also allow the fluid to drain.
The first few days can be a bit messy. I give patients lots of absorbent pads to catch the drainage, and two sets of compression garments, so that one can be washed while the other is in use. I encourage patients to wear loose garments like sweat suits that they might be willing to discard after the recovery period, and to cover their bedding and furniture until the drainage stops.
You may feel like you're leaking like a sieve, but it will be temporary, and it's a good thing.