Colitis

Digestive Disease Myths Slideshow

• Colitis Overview
• Colitis Causes
• Colitis Symptoms
• When to Seek Medical Care
• Exams and Tests
• Colitis Treatment
• Self-Care at Home
• Medical Treatment
• Medications
• Surgery
• Other Therapy
• Next Steps
• Follow-up
• Prevention
• Outlook
• Synonyms and Keywords
• Authors and Editors
• Pictures of Digestive Disease Myths - Slideshow
• Viewer Comments: Colitis - Describe Your Experience

Colitis Overview

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

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. As the liquid mixture of undigested food makes its journey, it mixes with mucus and normal bacteria residing in the colon. As well, water is reabsorbed into the bloodstream, and the feces start to solidify.

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 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 layers, or mucosa, come into contact with the fluid and allow water and electrolyte absorption to help solidify the feces. 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.

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 often present with bloody diarrhea and can cause significant dehydration.

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 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 narrow, the colon loses it's blood supply and becomes inflamed.

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

In patients 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 ate two types of inflammatory bowel disease. The first, 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 are generally abdominal pain and bloody bowel movements.

Crohn's disease is the second type of inflammatory bowel disease, and may involve any part of the digestive tract from the esophagus and stomach to both the small and large intestine. 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 by some layers of the colon wall becoming 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 auto-immune 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 the inflammation of the mucosal lining of the colon caused by harsh chemicals.

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