Colorectal surgery is a field in medicine dealing with disorders of the rectum, anus, and colon. The field is also known as proctology. The colon is an important segment of the whole alimentary tract. It forms majority of the distal portion of the digestive tract and is composed of the cecum which is the largest out-pouching of the intestines located at the right side of the abdomen; the ascending, transverse and descending colon; and the sigmoid which is the S-shaped region of the distal tract. It functions as a reabsorptive area for recyclable nutrients found in the digested material, as well as a storage area for faeces. Many advances in treating colon diseases such as tumours and inflammatory diseases are now treated with rectal surgery.