Abstract: The present invention is related to novel oral compositions comprising an irreversible gastric H+/K+-ATPase proton pump inhibitor (PPI) as a gastric acid secretion inhibitor, pentagastrin (PG) or a PG analogue as an activator of parietal cells in the gastric lumen. In a preferred embodiment, the composition further comprises at least one agent that preserves the availability of PG in the gastric fluids, thus enabling PG to act locally in the stomach. Unexpectedly, the compositions of the present invention exhibit anti-acid activity locally in the stomach that is meal-independent, exhibit fast onset and prolonged inhibition of acid secretion.