How does decreased serum protein lead to Ascites?

Question

Found this on notes: decreased colloidal osmotic pressure of plasma --> fluid escapes into extravascular compartment. But still, I don't understand.

Answer 1

All body compartments must stay isotonic. If protein in blood decreases, then that compartment becomes hypotonic with respect to the extravascular compartment. Water will flow from the hypotonic compartment into the other compartment. this causes ascites.

Osmosis: the movement of water across a semipermeable membrane from an area of higher concentration to an area of lower concentration (of the WATER).