The alimentary canal in a person or animal is the passage in their body through which food passes fromtheir mouth to their anus.
alimentary canal in British English
or alimentary tract
noun
the tubular passage extending from the mouth to the anus, through which food is passed and digested
alimentary canal in American English
or alimentary tract
the passage in the body through which food passes and in which it is digested, extendingfrom the mouth through the esophagus, stomach, and intestines to the anus