Colitis

Irritable Bowel Disease Slideshow Ulcerative Colitis Diet and Nutrition

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Colitis Overview
• Colitis Causes
• Colitis Symptoms
• When to Seek Medical Care for Colitis
• Colitis Diagnosis
• Colitis Treatment
• Colitis Self-Care at Home
• Colitis Medical Treatment
• Colitis Medications
• Colitis Surgery
• Other Therapy for Colitis
• Colitis Follow-up
• Colitis Prevention
• Colitis Prognosis
• Synonyms and Keywords
• Authors and Editors
• Pictures of Digestive Disease Myths - Slideshow
• Ulcerative Colitis Diet and Nutrition
• Viewer Comments: Colitis - Symptoms and Signs
• Viewer Comments: Colitis - Describe Your Experience

Colitis Overview

Colitis is a term used to describe inflammation of the colon. There are a variety of causes of colitis including infections, poor blood supply, and autoimmune reactions.

The colon is located in the abdominal cavity and is divided into the following parts: the cecum, the ascending colon, the transverse, the descending colon, the sigmoid, the rectum, and the anus. The right colon includes the cecum and ascending colon. The left colon includes the transverse segment to the sigmoid.

The colon (large bowel or large intestine) is responsible for collecting and storing the waste products of digestion. It is a long muscular tube that pushes undigested food towards the anus for eventual elimination as a bowel movement. Food is digested in the stomach into a liquid slurry that passes through the small intestine where the nutrients are absorbed into the body for use. When the liquid mixture enters the colon, it mixes with mucus and normal bacteria that reside in the colon. The wall of the colon has numerous layers. There is a smooth muscle layer that wraps the outside and is responsible for squeezing the undigested food through the length of the colon. The inner layer, or mucosa, comes into contact with the fluid and allows the absorption of water and electrolytes, which helps to solidify the feces (poop). The mucosal layer is where the colon inflammation occurs and is responsible for the symptoms of colitis.

As with any other organ, the colon has a blood supply with arteries delivering oxygen rich blood and nutrients to it, and veins that drain carbon dioxide and lactic acid from it. Diseases that decrease blood supply can cause inflammation of the colon.

Colitis Causes

Inflammation of the colon can be caused by a variety of illnesses and infections. Some of the most common causes are discussed below.

Infectious Colitis

Viruses and bacteria can cause colon infections. Most are food-borne illnesses or "food poisoning." Common bacterial causes include Shigella, E Coli, Salmonella and Campylobacter. These infections may cause bloody diarrhea and can result in significant dehydration.

Parasites such as giardia can cause significant diarrhea. The parasite can enter the body when infected water is swallowed. The source may be from recreational water such as rivers, lakes, and swimming pools. It may also be contaminated from a water well or cistern.

Pseudomembranous colitis is caused by the bacteria Clostridium difficile (C. difficile). This disorder is often seen in patients who have recently been taking antibiotics for an infection. The antibiotic alters the normal bacteria present in the colon and allows an overgrowth of the Clostridium bacteria. Clostridium bacteria produce a toxin that causes diarrhea. This is an infection, and often there is a fever present. The diarrhea is usually not bloody.

Ischemic Colitis

The arteries that supply blood to the colon are like any other artery in the body. They have the potential to become narrow due to atherosclerosis (just like blood vessels in the heart, which can cause angina, or narrowed vessels in the brain can cause a stroke). When these arteries become narrow, the colon may loose its blood supply and become inflamed.

The colon can also lose its blood supply for mechanical reasons. A couple of examples include volvulus, where the bowel twists on itself, or an incarcerated hernia, where a portion of the colon gets trapped in an outpouching of the abdominal wall, which prevents blood from flowing to the affected portion.

In individuals who are at risk for decreased blood flow to the colon, ischemic colitis can occur if the blood pressure falls. This may occur with dehydration, anemia, or shock.

Ischemia or lack of blood supply causes significant pain, fever, and bloody bowel movements.

Inflammatory Bowel Disease

There are two types of inflammatory bowel disease, ulcerative colitis, and Crohn's disease.

Ulcerative colitis is thought to be an autoimmune illness in which the body's immune system attacks the colon and causes inflammation. Ulcerative colitis begins in the rectum and may gradually spread throughout the colon. The signs and symptoms include abdominal pain and bloody bowel movements.

Crohn's disease may involve any part of the digestive tract from the esophagus and stomach, through to the small and large intestine all the way to the rectum. It often has skip lesions, that is diseased areas are interspersed with healthy areas of tissue.

Microscopic Colitis

Two diseases make up this group of colon inflammation, collagenous colitis and lymphocytic colitis. In these diseases, the inflammation is caused when the colon wall becomes engorged with either collagen or lymphocytes. Watery, non-bloody diarrhea is the most common symptom.

This is an uncommon illness that is seen more frequently in older women. The cause is unknown but an autoimmune potential may exist.

Chemical Colitis

If chemicals are instilled into the colon, inflammation and damage can occur. One of the complications of an enema is inflammation of the mucosal lining of the colon caused by harsh chemicals.