This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Physiology
In infants, defecation often following meal. The cause of colonic contraction in this situation is 
Select and explain. 
A. Gastroileal reflex, B. Enterogastric reflex, C. Increased circulation levels of CCK, D. Gastrocolic - reflex
D: Gastrocolic - reflex
Answer: D: Gastrocolic - reflex 
Explanation: Ans. (d) Gastrocolic - reflex(Ref: Ganong, 25th ed/p.504)Distension of the stomach by food - causes contractions of the rectum leading to defecation. This reflex is called gastrocolic reflex