POEM (Peroral Endoscopic Myotomy) is a modern method used in the treatment of achalasia. Achalasia is a motility disorder characterized by symptoms such as difficulty swallowing (dysphagia) after meals, a sensation of food sticking and obstruction in the chest, retrosternal discomfort, food regurgitation, infections that may result from aspiration into the lungs, bad breath, and chest pain.