“…Most of the data available in the adult population come from retrospective studies; investigations carried out in CD patients with symptoms suggesting upper GI involvement have reported the uncommon occurrence of a gastro-duodenal localization, ranging from 1 to 5% [2][3][4][5]. On the other hand, despite the low prevalence of symptomatic upper GI tract CD, routine upper endoscopy has revealed mild macroscopic gastro-duodenal lesions in 30-75% of CD patients [6,7], and microscopic inflammation in up to 70% of CD patients [8][9][10][11]. However, there is no recognized clinical correlate for these macroscopic and microscopic lesions, which may simply confirm that CD is an inflammatory pan-gastroenteric disorder.…”