Fig. 1

Case 1 (a–b). a: Indigo carmine spray enhancement and b: narrow-band imaging (NBI) of the duodenal second portion shows the edematous mucosa with villous atrophy. c: Magnifying endoscopic view with NBI of the duodenal second portion shows cerebriform or flat patterns with villous atrophy. d: Lower gastrointestinal (GI) endoscopic view of the ileocecal valves shows the edematous mucosa with small erosions; normal-looking mucosa is seen in the ascending colon