A Case of Ulcerative Colitis Complicated by a Simple Appendiceal OpeningXiao Liu1*, Fang Fang2，Qingfeng Luo11 Department of Gastroenterology, Beijing Hospital, National Center of Gerontology；Institute of Geriatric Medicine, Chinese Academy of Medical Sciences，P.R. China2 Department of pathology, Beijing Hospital, National Center of Gerontology；Institute of Geriatric Medicine, Chinese Academy of Medical Sciences，P.R. ChinaEmail: liuxiao3424@bjhmoh.cn