Several studies have identified a relationship between myelodysplastic syndrome and Behçet's disease (BD), especially intestinal BD, and trisomy 8 appears to play an important role in these disorders. Despite this, only few case reports or series have been reported in gastroenterology, meaning that endoscopic findings and characteristics of intestinal BD have not been clarified yet. In this report, we describe three cases of intestinal BD associated with myelodysplastic syndrome and trisomy 8, and discuss the clinical features and problems of these disorders from a gastroenterology perspective.