<prompt> Investigation of choice for Zenkers diverticulum is:CECTEndoscopyEsophageal manometryBarium Swallow  <response>: Once suspected, the diagnosis is established by a barium swallow. Endoscopy is usually difficult in the presence of a cricopharyngeal diverticulum; and potentially dangerous, owing to obstruction of the true esophageal lumen by the diverticulum and the attendant risk of diverticular perforation.- Schwartz 