Does a Sea Star have a one way stomach or two?

A sea star has a unique feeding mechanism that involves a one-way stomach. When it captures its prey, usually bivalves, it can evert its stomach through its mouth and into the shell of the prey to digest it externally. This allows the sea star to absorb nutrients directly from the digested material before retracting its stomach back into its body. Thus, it effectively has a single, functional digestive cavity.