Bile reflux is primarily caused by the malfunctioning of the lower esophageal sphincter (LES), a muscular valve located between the esophagus and the stomach.
Here's a more detailed explanation:
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The Role of the Lower Esophageal Sphincter (LES): The LES normally opens to allow food and liquids to pass from the esophagus into the stomach and then closes to prevent stomach contents, including bile and stomach acid, from flowing back up (refluxing) into the esophagus.
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LES Dysfunction: When the LES is weakened or relaxes inappropriately, it allows bile (produced in the liver and stored in the gallbladder) and stomach acid to back up into the esophagus. This backflow irritates the lining of the esophagus, leading to inflammation and symptoms of bile reflux.
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Contributing Factors: Several factors can contribute to LES dysfunction, including:
- Hiatal Hernia: A condition where a portion of the stomach protrudes through an opening in the diaphragm, which can weaken the LES.
- Surgery: Previous surgeries involving the stomach or esophagus can sometimes damage or weaken the LES.
- Medications: Certain medications, such as calcium channel blockers, nitrates, and some antidepressants, can relax the LES.
- Smoking: Smoking can weaken the LES.
- Obesity: Excess weight can increase pressure on the stomach, leading to LES relaxation.
In summary, bile reflux occurs when the LES doesn't function properly, allowing bile and stomach acid to flow back into the esophagus. This dysfunction can be caused by various factors such as hiatal hernias, surgery, medications, and lifestyle choices.
