A patient present with dysphagia of 4 weeks duration. Now he is able to swallow liquid food only. Which of the following is the one investigation to be done:

Answer is B (Upper GI endoscopy is to be done) The patient is presenting with new onset dysphagia for solids alone (able to swallow liquids). This suggests dysphagia due to mechanical obstruction (carcinoma, stricture, web) which is best diagnosed by endoscopy. Note: Barium swallow is the recommended initial investigation Endoscopy is the investigation of choice.