An ulcer is a digestive disorder caused by a bacteria known as Helicobacter pylori (H. pylori), which produces a substance that weakens the mucous lining in the stomach. This causes the digestive juices to burn the internal side of the stomach, resulting in a burning sensation, and pain in the stomach.
Related: How to Treat Peptic Ulcer
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Acid reflux, on the other hand, is a condition where the one-way valve at the end of the oesophagus relaxes, allowing the digestive juices in the stomach to flow back into the oesophagus - this causes a person to feel a burning sensation in the chest region. Normally the valve, lower esophageal sphincter (LES), closes as soon as the food goes through it into the stomach, but under certain conditions, the LES stops functioning efficiently, and some of the acid from the stomach flows back into the oesophagus, leading to acid reflux.
Suggested: How to Deal With Bile Reflux
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