A 20 yr old male presented to the opd with complaints of slight difficulty in swallowing and a foreign body sensation in the throat for the past 3 years...He also complaints of production of slight amounts of sputum occasionally w/o cough.Clinical examination revealed slight congestion of pharynx... A throat swab was taken and came back negative... A barrium swallow was done and was normal... Doctor send him home saying that he is fine and there is no need of doing further investigations like CT or MRI as the previous tests were normal... Diagnosis?