Large intestine, posterior section of the intestine, consisting typically of four regions: the cecum, colon, rectum, and anus. The term colon is sometimes used to refer to the entire large intestine.
The large intestine is wider and shorter than the small intestine (approximately 1.5 metres, or 5 feet, in length as compared with 6.7 to 7.6 metres, or 22 to 25 feet, in length for the small intestine) and has a smooth inner wall. In the proximal, or upper, half of the large intestine, enzymes from the small intestine complete the digestive process, and bacteria produce B vitamins (B12, thiamin, and riboflavin) as well as vitamin K. The primary function of the large intestine, however, is absorption of water and electrolytes from digestive residues (a process that usually takes 24 to 30 hours) and storage of fecal matter until it can be expelled. Churning movements of the large intestine gradually expose digestive residue to the absorbing walls. A progressive and more vigorous type of movement known as the gastrocolic reflex, which occurs only two or three times daily, propels the material toward the anus.
Common afflictions of the large intestine include inflammation, such as
and abnormal growths, such as benign or malignant tumours.
human digestive system: Large intestine
The large intestine, or colon, serves as a reservoir for the liquids emptied into it from the small intestine. It has a much larger diameter than the small intestine (approximately 2.5 cm, or 1 inch, as opposed to 6 cm, or 3 inches,…
digestive system disease: Large intestine
A wide variety of diseases and disorders occur in the large intestine. Abnormal rotation of the colon is fairly frequent and occasionally leads to disorders. Unusually long mesenteries (the supporting tissues of the large intestine) may permit recurrent twisting, cutting off the blood…
nutritional disease: Bowel conditions and diseases
By drawing water into the large intestine (colon), fibre—especially the insoluble type—helps form a soft, bulky stool. Eating dried fruits such as prunes, which contain a natural laxative substance (dihydroxyphenyl isatin) as well as being high in fibre, also helps stimulate the bowels. Although laxatives or enemas may be helpful,…
…growth of cells within the large intestine (colon) or rectum (terminal portion of the large intestine). Colon cancer (or bowel cancer) and rectal cancer are sometimes referred to separately. Colorectal cancer develops slowly but can spread to surrounding and distant tissues of the body.…
In the large intestine (or colon), the peristaltic wave, or mass movement, is continuous and progressive; it advances steadily toward the anal end of the tract, pushing waste material in front of the wave. When these movements are vigorous enough to pass fecal masses into the rectum,…