<prompt> Bird beak appearance on barium swallow study in seen in -Achlasia cardiaCarcinoma esophagusHiatus herniaDiffuse esophageal spasm  <response>: Ans. is a i.e., Achlasia cardia o Bird beak appearance on barium study is seen in achlasia cardia.Important esophageal signsSignConditionRat tail appearance of esophagus MaharashtraEsophageal carcinomaMegaesophagus sigmoid esophagusBird beak appearanceHurst phenomenonAchalasia cardiaYo-Yo motion of barium Corkscrew appearanceesophageal curlingRosary-beadsheikh kebab configurationChain of bead appearanceDiffuse esophageal spasm 