gastrointestinal tract vs digestive tube

gastrointestinal tract and digestive tube both are nouns.

Word	Noun	Adjective	Verb	Adverb
gastrointestinal tract	Yes	No	No	No
digestive tube	Yes	No	No	No

As nouns, gastrointestinal tract and digestive tube are synonyms defined as:

gastrointestinal tract and digestive tube: tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination

Other synonyms of gastrointestinal tract include alimentary canal, alimentary tract, digestive tract, GI tract.

gastrointestinal tract (noun)	digestive tube (noun)
tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination	tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination