The Gastro-Oesophageal Valve
The Gastro-oesophageal Valve has two components: the lower oesophageal sphincter muscle (the circular muscle fibres which squeeze the passage shut) and the slit-like opening in the diaphragm muscle through which the oesophagus passes (the diaphragm hiatus).
Individually these two components are weak, but when working together they provide a tight junction.
The function of this junction is very complex, and in the normal situation it is controlled by various reflexes.
When we swallow, for example, the junction is required to relax at just the right time to allow food into the stomach, but when we are not swallowing the junction must remain tight to prevent gastro-oesophageal reflux.
Problems with the valve There are two main reasons why you may develop problems with your gastro-oesophageal valve.
These may occur alone or together.
The sphincter muscle at the bottom of the oesophagus may relax too much, or you may develop a fault where the oesophagus goes through the diaphragm - a hiatus hernia.
Sphincter muscle problems In some people there may be no obvious explanation why this muscle does not function as it should, but factors that are known to play a part are: being overweight, heavy alcohol consumption, smoking, certain foodstuffs (fatty foods, onions, spicy foods, chocolate and acidic foods) and occasionally prescribed drugs.
All of these are more likely to cause problems near bedtime, so that you are at increased risk of reflux when you lie down.
Hiatus hernia Sometimes, the hiatus (opening) in the diaphragm is too large, allowing the upper part of the stomach to slip above the diaphragm.
The result is that the two parts of the gastro oesophageal valve are no longer aligned, thus reducing its strength and allowing reflux of acid into the oesophagus.
Having a hiatus hernia does not always cause symptoms in fact most people do not get any.
What hiatus hernias do is make gastro-oesophageal reflux more likely and this is what causes the symptoms.
No one knows why a hiatus hernia may develop, but they are known to be extremely common (especially in those aged over 65 years) and often they go undetected, causing no trouble throughout a person's whole life.
Individually these two components are weak, but when working together they provide a tight junction.
The function of this junction is very complex, and in the normal situation it is controlled by various reflexes.
When we swallow, for example, the junction is required to relax at just the right time to allow food into the stomach, but when we are not swallowing the junction must remain tight to prevent gastro-oesophageal reflux.
Problems with the valve There are two main reasons why you may develop problems with your gastro-oesophageal valve.
These may occur alone or together.
The sphincter muscle at the bottom of the oesophagus may relax too much, or you may develop a fault where the oesophagus goes through the diaphragm - a hiatus hernia.
Sphincter muscle problems In some people there may be no obvious explanation why this muscle does not function as it should, but factors that are known to play a part are: being overweight, heavy alcohol consumption, smoking, certain foodstuffs (fatty foods, onions, spicy foods, chocolate and acidic foods) and occasionally prescribed drugs.
All of these are more likely to cause problems near bedtime, so that you are at increased risk of reflux when you lie down.
Hiatus hernia Sometimes, the hiatus (opening) in the diaphragm is too large, allowing the upper part of the stomach to slip above the diaphragm.
The result is that the two parts of the gastro oesophageal valve are no longer aligned, thus reducing its strength and allowing reflux of acid into the oesophagus.
Having a hiatus hernia does not always cause symptoms in fact most people do not get any.
What hiatus hernias do is make gastro-oesophageal reflux more likely and this is what causes the symptoms.
No one knows why a hiatus hernia may develop, but they are known to be extremely common (especially in those aged over 65 years) and often they go undetected, causing no trouble throughout a person's whole life.