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Ulcerative Colitis

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Anatomy of the Gastrointestinal System and Ulcerative Colitis

The digestive system, is also called the gastrointestinal, or GI, system.

The GI system: After food is chewed and swallowed, it travels through the esophagus to the stomach. There it is partly broken down and then sent to the small intestine, also known as the small bowel. The word "small" refers to the diameter of the small intestine, which is narrower than that of the large bowel. Actually the small intestine is the longest segment of the digestive system -- about 20 feet. The small intestine continues breaking down the food and absorbs most of the nutrients. The small bowel joins the colon in the right lower abdomen.

The colon (also called the large bowel or large intestine) is a muscular tube about 5 feet long. The large intestine consists of the colon and the rectum. The colon is the first 4 to 5 feet of the large intestine, and the rectum is the last 4 to 5 inches of the large intestine. The part of the colon that joins to the rectum is the sigmoid colon. The colon continues to absorb water and mineral nutrients from the food matter and serves as a storage place for waste matter. The waste matter left after this process is feces and goes into the rectum, and from there it passes out of the body through the anus.(2)

Ulcerative colitis is a chronic, episodic, inflammatory disease of the large intestine and rectum characterized by bloody diarrhea.

The disease usually begins in the rectal area and may eventually extend through the entire large intestine.

Ulcerative colitis is categorized according to location:

  • Proctitis involves only the rectum
  • Proctosigmoiditis affects the rectum and sigmoid colon
  • Left-sided colitis encompasses the entire left side of the large intestine
  • Pancolitis refers to inflammation of the entire colon

To understand more about the anatomy of the gastrointestinal system, click here to view a selection of well-illustrated interactive antomical videotutorials

Inflammatory bowel disease falls under two main headings: Crohn's disease, which involves the entire GI tract, and ulcerative colitis, which involves only the colon. Inflammatory bowel disease is a condition in which the innner lining of the GI tract becomes inflamed, leading to ulcers and bleeding. The colon is most often the site of this inflammation. Patients with inflammatory bowel disease have symptoms that include diarrhea, abdominal pain, infections, and bleeding.
Clinical Trials on Ulcerative Colitis A service of the U.S. National Institute of Health
Support Groups in Pinellas County, Florida
Crohn's and Colitis Support Group
7pm, First Tuesday of every month, Morton Plant Hospital, 300 Pinellas Street, Clearwater
Call (727) 723-2207
Educational Video Tutorials
Ulcerative Colitis from Medline Plus, a service of the Nat'l Library of Medicine and the Nat'l Institute of Health
Internet References for Ulcerative Colitis
About Ulcerative Colitis and Proctitis an 8-page handout from the Crohn's and Colitis Foundation of America
Living with Ulcerative Colitis
a 12-page brochure (PDF) from the Crohn's and Colitis Foundation of America
A Guide for Parents
a 14-page brochure (PDF) from the Crohn's and Colitis Foundation of America
A Guide for Teachers and other School Personnel
an 8-page brochure (PDF) from the Crohn's and Colitis Foundation of America
More Educational Brochures for Ulcerative Colitis
Ulcerative Colitis from the National Digestive Diseases Information Clearinghouse (NDDIC)
Ulcerative Colitis from the Mayo Clinic
Measles Vaccine and Inflammatory Bowel Disease from the Center for Disease Control (CDC)
What People with Inflammatory Bowel Disease Need to Know about Osteoporosis from the National Institute of Arthritis and Musculoskeletal and Skin Disease
Inflammatory Bowel Disease from the Nemours Foundation
American Society of Colon and Rectal Surgeons
--Written by N Thompson, ARNP Last updated May 2007

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