Digestive system
From Memory Alpha, the free Star Trek reference
The Digestive system is the bodily system that serves the purpose of breaking food down into its nutritional components.
When Lwaxana Troi was attracted to Odo in 2369, he attempted to lose her interest in that he couldn't eat as he did not have a digestive system. (DS9: "The Forsaken")
The Doctor was going to have a present topic on Hints for Healthful Living about the Bolian digestive system. (VOY: "Investigations")
Both the USS Enterprise and the USS Voyager have been almost eaten inside of the digestive systems of spaceborne species. (TAS: "One of Our Planets Is Missing"; VOY: "Bliss")
The ambient sounds that Gomtuu made were derived from sounds recorded from sound effects editor Jim Wolvington's stomach through a stethoscope while he was eating pizza. (Star Trek: The Next Generation Companion)
