A 42-year-old woman has heartburn after meals and a sour taste in her mouth. For the past 4 to 6 months she has had symptoms several times a week. Symptoms are worse when she lies down or bends over. Antacids help somewhat. The patient has no dysphagia, vomiting, abdominal pain, exertional symptoms, melaena, or weight loss. Past medical history and family history are non-contributory. The patient drinks alcohol occasionally and does not smoke. On physical examination, height is 1.63 m (5 feet 4 inches), weight 77.1 kg, and BP 140/88 mmHg. The remainder of the examination is unremarkable. What is the diagnosis?
Gastro-oesophageal reflux disease.