Thanks nisreen ,
actually in decks it was written that the epithelium gets converted to simple columnar here ,so ....
moreover,i also found out that it is stratified squamous nonkeratinized bit gets converted to sinple columnar in lower third .if any changes please let me know
the distal esophagus is lined with nonkerat squamous epithelium. It gets converted to columnar epithelium (same as gastric epithelium) when there is chronic gastric acid reflux. The metaplasia is called Barret's esophagus. The process has the possibility of becoming cancerous (adenocarcinoma).