cecumListen to pronunciation(SEE-kum)A pouch that forms the first part of the large intestine. It connects the small intestine to the colon, which is part of the large intestine.Enlarge this image in new windowThe cecum connects the small intestine to the colon. The colon includes the ascending colon, transverse colon, descending colon, and sigmoid colon. The sigmoid colon connects to the rectum and anal canal, which leads to the outside of the body.Search NCI's Dictionary of Cancer TermsStarts withContainsBrowse:ABCDEFGHIJKLMNOPQRSTUVWXYZ#