Group 7 initial D is comprised of four members: Qihang, Zhou Bo, Marcus, and Bryan. Their document summarizes the key parts and functions of the human digestive system, including the anus, rectum, and appendix. It describes how the external and internal sphincters of the anus work to control bowel movements. It also outlines common illnesses that can affect the anus and rectum, such as hemorrhoids, fissures, and rectal bleeding. The location and potential functions of the appendix are explained, as well as its main disease, appendicitis. Acknowledgements are provided for the sources of information.