The human gastrointestinal tract, or GI tract, is an organ system responsible for consuming and digesting food, absorbing nutrients and expelling waste. The tract consists of the stomach and intestines, and is divided into the upper and lower gastrointestinal tracts.

The digestive tract includes the esophagus (or food tube), stomach, small intestine and colon or large intestine/bowel. It begins at the mouth and ends at the anus. Gut motility is the term given to the stretching and contractions of the muscles in the gastrointestinal tract.