Metoclopramide:
Ans. (D) Enhances colonic motility(Ref: Katzung 10/e p1021; KDT 8th/e p713)Metoclopramide is a D2 receptor antagonist that increases cholinergic activity by inhibiting presynpatic D2 receptors in GIT (D2 receptor stimulation inhibits the release of ACh).It increase LES tone that is also responsible for anti-emetic action.It does not significantly increase colonic motility.But out of the four options, this is the best answer, because although not significantly but it can increase colonic motility, whereas other options are definitely wrong.
Inhibit cholinergic smooth muscle stimulation in the gastrointestinal tract
Decrease lower esophageal sphincter pressure
Stimulate D2 receptor
Enhance colonic motility
Anti-Emetic