Upper gastrointestinal (GI) lesions are frequently reported in Crohn's disease, in which the entire GI tract is affected. In these cases, erosive fissures regularly transversing folds that are longitudinally aligned along the lesser curvature of the gastric body and cardia are described as having a "bamboo joint-like appearance". We designed a blinded experiment in which upper GI imaging without a final diagnosis was checked by three observers to determine the usefulness of the bamboo joint-like appearance in the diagnosis of Crohn's disease. For the three observers, sensitivities of appearance were 30.5%, 56.9%, and 51.4%, while specificities were 99.6%, 98.5%, and 99.3%. Thus, the bamboo joint-like appearance was not useful for the identification of Crohn's disease patients. Nevertheless, patients exhibiting the bamboo joint-like appearance in upper GI imaging should undergo further examination due to the high probability of Crohn's disease.