The colon is located in the abdominal cavity, framing the small intestine. It can be divided into several sections: the input part is the cecum, followed by the ascending colon, then the transverse colon, the descending colon, and the sigmoid colon.
The last section of the colon is the rectum, which is located in the pelvis. Of the two curves, the greater lies in the concavity of the sacrum, and the shorter, of opposite curvature, passes through the perineum, fused with its muscles.
The opening of the outlet of the rectal sacrum is the anus. It is operated by two sphincters, the internal, non-voluntary and the external voluntary sphincter. These ensure voluntary stool retention as well as defecation.
The proctologist is a specialist in the lesions and diseases that develop at this stage of the colon.