When you eat and swallow, food entering the stomach is prevented from washing back into the lower esophagus by a muscular valve, or sphincter. When the sphincter isn't tight enough, stomach acids and even bits of food can squirt back into the esophagus and irritate its nerve-filled lining, giving rise to all the discomfort and that bitter taste. Many factors can cause the sphincter to be too relaxed. One cause is hiatal hernia - a common congenital abnormality in which the top of the stomach protrudes through an opening where the esophagus passes through the diaphragm. Smoking, obesity, and pregnancy may also be to blame.
Doctors recommend trying some lifestyle changes to prevent the condition in the first place.
Losing excess weight can also help. Wolfe and other experts say it's fine to take the nonprescription drugs for occasional heartburn symptoms. But if you find yourself taking them twice a week or more, it's time to see the doctor. The doctor may order an upper GI series of X-rays or endoscopy, where a flexible tube is passed down your esophagus to examine the stomach. One concern is that longstanding reflux may cause Barrett's esophagus, a precancerous change in the lining of the lower esophagus.