Stomach

The stomach was the organ used for digesting food. The Sarlacc took a millennium to digest its victims, an agonizing execution that Jabba the Hutt planned to subject Luke Skywalker, Han Solo and Chewbacca to.

Later on Endor, Han admonished Chewbacca for thinking with his stomach after he pulled a carcass and got them caught in an Ewok booby trap.

Behind the scenes
StarWars.com clarifies that the Millennium Falcon was in the gullet of the space slug, not its stomach.

Appearances

 * The Rebellion Begins
 * Servants of the Empire: Rebel in the Ranks
 * Star Wars: Episode VI Return of the Jedi