X anal sigmoid colon drawing
Sigmoidoscopy is a procedure used to see inside the sigmoid colon and rectum. The sigmoid colon is the area of the large intestine nearest to the rectum. Your health care provider will tell you how to prepare for the exam. You will use an enema to empty your bowels.
Mapping the body: the sigmoid colon
The Small and Large Intestines | Anatomy and Physiology II
The large intestine , also known as the large bowel , is the last part of the gastrointestinal tract and of the digestive system in vertebrates. Water is absorbed here and the remaining waste material is stored as feces before being removed by defecation. The colon  is the largest portion of the large intestine, so many mentions of the large intestine and colon overlap in meaning whenever anatomic precision is not the focus. Most sources define the large intestine as the combination of the cecum , colon, rectum , and anal canal. In humans, the large intestine begins in the right iliac region of the pelvis , just at or below the waist , where it is joined to the end of the small intestine at the cecum, via the ileocecal valve.
Anatomic Problems of the Lower GI Tract
The sigmoid colon or pelvic colon is the part of the large intestine that is closest to the rectum and anus. This part of the colon normally lies within the pelvis , but on account of its freedom of movement it is liable to be displaced into the abdominal cavity. The sigmoid colon begins at the superior aperture of the lesser pelvis , where it is continuous with the iliac colon , and passes transversely across the front of the sacrum to the right side of the pelvis.
Chyme released from the stomach enters the small intestine , which is the primary digestive organ in the body. Not only is this where most digestion occurs, it is also where practically all absorption occurs. The longest part of the alimentary canal, the small intestine is about 3. This large surface area is necessary for complex processes of digestion and absorption that occur within it. The coiled tube of the small intestine is subdivided into three regions.