<unk>  refers to an abnormal change (metaplasia) in the cells of the lower end of the<unk>  thought to be caused by damage from chronic acid exposure, or reflux esophagitis. It is a condition in which any extent of metaplastic columnar epithelium replaces the normal stratified squamous epithelium in the distal<unk> . Intestinal metaplasia is required for the diagnosis of<unk> .
Barrett's esophagus
Nutcracker esophagus
Zenker's diverticulum
Achalasia
Esophageal candidiasis
CMV esophagitis
Eosinophilic esophagitis
Gastric diverticulum