Which of the following statements about achalasia is/are correct?

D. Manometry demonstrates failure of LES relaxation on swallowing and absent or weak simultaneous contractions in the esophageal body after swallowing.

DISCUSSION: While in South America achalasia is the result of Chagas' disease caused by parasitic infestation by the leishmanial forms of T. cruzi, in Europe and North America the cause of achalasia is unknown. The common presenting symptoms of achalasia are dysphagia, regurgitation, and weight loss. Chest pain is an infrequent symptom in achalasia and is more characteristic of esophageal spasm. Achalasia is a premalignant esophageal lesion: the retention esophagitis leads to metaplasia and squamous cell carcinoma, which occurs after 15 to 25 years in the middle third of the thoracic esophagus in 10% of patients. The classic manometric findings of achalasia are failure of relaxation of the LES on swallowing and absent or weak simultaneous contractions in the esophageal body after swallowing. Achalasia is currently incurable, and, though the recently described endoscopic botulinum toxin injection of the lower esophageal sphincter, pneumatic dilatation, and esophagomyotomy effectively relieve dysphagia in the majority of patients, all of these treatments are strictly palliative. The motility disturbance persists throughout life.