The beginning of the colon is called the cecum. It begins in the lower right portion of the abdomen where last part of the small intestine (ileum) empties into the large intestine. This part of the colon is called the cecum. It also is where the appendix attaches. The segments of the colon in order from the beginning of the colon or cecum going distally are ascending, transverse, descending, sigmoid colon and rectum.
The major function of the colon is to recycle water for the body. Removing the water from the stool allows the body to conserve fluid and the stool to be formed or semisolid. When the entire colon is present and healthy the stools have only enough water in them to soft and easy to pass but not so watery or loose that leakage occurs and dehydration ensues. When a large part of the colon is removed or when the colon is injured significantly, the stools are very watery and frequent.
You can live without your colon though stools will be looser formed or watery and more frequent. When the entire colon is removed it is called a total colectomy. When less than the entire colon is removed it is called a subtotal colectomy or a segmental colectomy if only a segment or segment is removed.