Also known as oesophageal achalasia, this is a disorder where there is dysphagia caused by the lower oesophageal sphincter being inable to relax on swallowing to allow food to pass into the stomach. The patient with achalasia will feel a bolus of food retrosternally, which "sticks there" for a period of time before finally "going through".
Diagnosis is via a careful history and endoscopy or barium swallow X-rays. Endoscopy is preferred as it allows biopsies to be taken during the test for histological examination.
Treatment involves either injection of botulinum toxin, pneumatic (balloon) pumping (now less popular) and surgery.