This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
POEM is done for which of the following disease 
Select and explain. 
A. Achalasia cardia, B. Hiatus hernia, C. Diffuse esophageal spasm, D. Esophageal carcinoma
A: Achalasia cardia
Answer: A: Achalasia cardia 
Explanation: Answer- A. Achalasia cardiaTreatment of achalasia cardiaThe aim of treatment is to be relieve the functional obstruction at the cardiaThe two main methods to achieve this areForceful dilatation orEsophageal myotomy (Heller's myotomy) with or without an antireflux procedurePer-oral endoscopic myotomy (POEM)It is now the preferred method by some surgeones.It is an endoscopic procedure in which myotomy is done under guidance of endoscope introduced by oral route.