Marshmallow is a demulcent herb, which means it appears to operate by reducing inflammation and establishing a barrier against irritants like stomach acid. More. Demulcent herbs can help with indigestion and heartburn. Acid reflux is when stomach acid comes back up into your esophagus. This happens when there is pressure on the lower end of the esophagus from something heavy for example food. The pressure forces the acid up through the esophagus into the mouth. If you are eating foods that are hard to digest or contain alcohol then this will exacerbate the problem. If you are using antacids then this is not a good idea because they will neutralize the acid in your stomach and prevent it from breaking down food. Instead, try eating small meals frequently throughout the day, including some protein and carbohydrates with each meal. This will help keep you fuller longer which should reduce the need for excess consumption at one time. Of course, if you experience pain when you breathe in then you should see your doctor. Acid reflux can lead to other problems such as esophageal cancer so it's important to get checked out by a physician if you have any risk factors for developing this disease. The best way to avoid acid reflux is by avoiding the causes.