A 26-year-old business executive complained of a dull pain (heartburn) behind the sternum. The pain was postprandial (occurred after meals) and disappeared within a few minutes to an hour. It was often associated with belching and often was worse on lying down or on exertion after heavy meals. Sometimes it radiated to the back, jaws, shoulders, and down the inner aspects of the arms, simulating angina pectoris. X-rays revealed a small portion of the stomach above the diaphragm, and an endoscopic biopsy revealed mucosal inflammation. Esophageal manometry (determining pressures at the lower esophageal sphincter, LES) revealed decreased LES pressure. Esophageal pH monitoring showed reflux of gastric contents into the esophagus and provided direct evidence of gastroesophageal reflux. Recommended treatment for this individual is avoidance of strong stimulants of gastric acid secretion (e.g., coffee, alcohol) and avoidance of certain drugs (e.g., anticholinergics), and specific foods (fats, chocolates, whole milk, and orange juice), and smoking, all of which reduce LES competence. Elevation of the head of the bed by about six inches is also recommended. Suggested treatments also include the use of cholinergic agonists (e.g., bethanechol) and the use of histamine (H2) antagonists.

1. What is the disorder of this 26-year-old business executive? Explain.

2. What mechanisms normally prevent gastric reflux into the esophagus when lying down or bending over?

3. Why are anticholinergic agents avoided and cholinergic agonists recommended in the treatment of gastroesophageal reflux?

4. Why are histamine (H2) antagonists recommended?