digestive tract

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The mucous membrane–lined tube of the digestive system through which food passes, in which digestion takes place, and from which wastes are eliminated. It extends from the mouth to the anus and includes the pharynx, esophagus, stomach, and intestines.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun System of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and expels the remaining waste.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun tubular passage of mucous membrane and muscle extending about 8.3 meters from mouth to anus; functions in digestion and elimination