There is also a band of muscle at the bottom of the oesophagus where it joins the stomach, which can weaken
with age
or too much acid splash back, which allows acid into the oesophagus. This isn't good because it has no protection from the acid, becomes damaged and inflamed, and very painful. Proton pump inhibitors such as omeprazole ensure your stomach produces less acid, giving help for repair of ulcers, or helping with acid reflux in the oesophagus.