Suggest Treatment For Persistent Cough And Difficulty Swallowing

Hello Doctor, My son is 14 years and was coughing daily night for almost 4 months, and went to doctor 4 times in 4 months, and I asked the hospital to give me the weight details of my son’s first visit and last visit, and asked them to refer to Gastroenterologist, because he lost almost 35 pounds in 4 months. The blood samples they came negative and the Upper GI X-ray showed him that he has Achalasia cardia and the X-Ray specialist say this problem for the kid is from the birth, I am unable to believe that. My son never had difficulty in swallowing till today or any chest pain. He was eating well. Can you please suggest? Thanks Vijay