Hi - Digestive bitters stimulate hydrochloric acid production as well as pancreatic and biliary secretions. I take them as needed when my digestion is starting to feel a little sluggish. They are available in most health food stores. Swedish Bitters are the most popular brand. I can't remember what country they are from . . . . ;-)
But seriously folks, hydrochloric acid supplements are for shortterm use until you stomach resumes producing it on its own. Digestive bitters can be used ongoing, and can be used longterm if needed.