Fig. 1

Colonoscopic findings and light microscopic images on the initial colon biopsy. Redness, erosions, and segmental ulcers are observed in the ascending colon (a), transverse colon (b), and sigmoid colon (c). In contrast, there are no rectal involvements (d). Light microscopic images show loss of glands and fibrosis in the mucosa of the ascending colon (e) and congestion, edema, and partial loss of glands in the transverse colon (f); these findings are compatible with ischemic colitis. Hyperplastic glands with dilatation can be observed in the sigmoid colon, with no other specific findings such as infection (g)