How do they drain away the fluid from the abdomen?

With a tiny needle: After local anesthesia, a small needle is inserted just below the belly button. Fluid comes out easily and drains.

Needle: The medical term for the procedure is paracentesis (pair-a-sen-tee-sis). It's not complicated. A needle is inserted into the abdoman, hooked to a tube and plastic bag to cllect the fluid. It's a very safe procedure. Local anesthesia usually is given, but even without it, this isn't a big deal.