Acid Reflux

Acid reflux, also known as gastroesophageal reflux disease (GERD) or chronic heartburn, is a medical condition characterized by abnormal backflow of acid from the stomach to the esophagus. It is one of the most common disorders of the gastrointestinal tract and it is estimated that 3 to 4 percent of the population has GERD, while up to 40 percent of the population experience heartburn, the most common symptom associated with GERD, at least once a month. The various causes of acid reflux generally lead to the same symptoms and can be diagnosed through a careful patient history and some diagnostic exams. Treatment ranges from conservative management through lifestyle changes, to the use of medications and potentially to surgery. Possible complications from untreated acid reflux include Barrett's esophagus and esophageal cancer.

In normal individuals, acid is secreted in the stomach to aid in the digestion of food. This acid is usually kept in the stomach and prevented from flowing backward into the esophagus by a zone of constricting muscles called the lower esophageal sphincter (LES). The strength of the LES is also supported anatomically by the muscles of diaphragm. Generally speaking, acid reflux occurs when the LES fails to keep acid and stomach contents from refluxing into the esophagus. The various causes of acid reflux fall into two general categories: decreased strength or tone of the LES and increased stomach filling.

Decreased LES tone is associated with pregnancy, smoking, certain drugs (anticholinergic drugs and smooth muscle relaxants), foods (fatty foods, peppermint, chocolate), previous surgery (especially Heller myotomies for achalasia), and hiatal hernias (where the LES is displaced from its normal location below the diaphragm to above it). Increased gastric filling is associated with the ingestion of large meals, [Page 6]hypersecretion of acid (as can be seen in Zollinger-Ellison syndrome), and decreased stomach motility.