Fig. 3
a A macroscopic view of the resected specimen shows atrophic mucosa in the distal colon, whereas edematous mucosa and luminal dilatation are seen in the proximal colon. The coloanal anastomosis was stenotic (arrow head) and a fistula (arrow) was found proximal to the anastomosis. b–d A histological examination with hematoxylin and eosin staining exhibited erosion and ulceration, a crypt abscess, and severe inflammatory infiltration in the colonic mucosa with original magnification of × 100, × 40, and × 200, respectively