Intestine

"The intestines are a long, continuous tube running from the stomach to the anus. Most absorption of nutrients and water happen in the intestines. The intestines include the small intestine, large intestine, and rectum.
The small intestine (small bowel) is about 20 feet long and about an inch in diameter. Its job is to absorb most of the nutrients from what we eat and drink. Velvety tissue lines the small intestine, which is divided into the duodenum, jejunum, and ileum.
The large intestine (colon or large bowel) is about 5 feet long and about 3 inches in diameter. The colon absorbs water from wastes, creating stool. As stool enters the rectum, nerves there create the urge to defecate."

Cryptitis

Cryptitis is a term that is used to describe one of the abnormalities that is seen under the microscope when tissue from the small intestinal or colon is examined. The crypts are normal tubular structures composed of cells that extend into the walls of the intestines. These crypts contain the cells that give rise to all of the other cells that migrate out of the crypts and then line the inner surface of the intestines. Inflammation of the crypts is known as cryptitis. Cryptitis is seen in inflammatory bowel disease, both Crohn's and ulcerative colitis, but it also can be seen in other inflammatory conditions of the intestines. It is not a disease itself but a microscopical manifestation of several different diseases.