Figure 1 Macroscopic (A) and histological appearance (B) of normal oesophagus and reflux oesophagitis. Normal oesophagus has a thin epithelial layer with few inflammatory cells. However, several erosions and ulcers, and histological defects of the epithelium and marked inflammatory cell infiltration are observed on day 3 (acute phase). Oesophageal lesions with mucosal thickening with basal cell hyperplasia, elongation of lamina propria papillae, and inflammatory cell infiltration were found in the middle and lower parts of the oesophagus on day 21 (chronic phase).