In infants, defecation often follows a meal. The cause of colonic contractions in this situation is
High-Yield Explanation
(Gastrocolic reflex) (511- Ganong) (477- Ganong 23rd)* Distention of the stomach by food initiates contactions of the rectum and , frequently a desire to defecate. The response is called the Gastrocolic reflex* Some evidence that it is due an action of gastrin on the colon and is not neurally mediated* When food leaves the stomach, the cecum relaxes and the passage of chyme through the ileocecal valve increases (Gastroileal reflex). This is presumably a vagal reflex.