溃疡性结肠炎(ulcerous colonitis UC)是一种发病机理不明的慢性炎症性肠道病变,以黏膜充血、溃疡糜烂为主要病理表现,主要累及直肠和乙状结肠,也可侵及结肠其他部分或整个结肠。病变严重者,或可出现10cm以内的返流性回肠炎(backward ileitis)。临床症状以黏液血便、腹痛、腹泻 Ulcerous colonitis (UC) is a chronic inflammatory bowel disease with unknown pathogenesis. Mucosal hyperemia and ulcer erosion are the main pathological manifestations, which mainly involve the rectum and sigmoid colon, and can also invade other parts of the colon or the entire colon . Serious lesions, or there may be less than 10cm of ileitis (backward ileitis). Clinical symptoms with mucus bloody stool, abdominal pain, diarrhea