COLITIS---INFLAMMATION OF COLON(ABDOMINAL PAIN)

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: thececum, the ascending colon, the transverse, the descending colon, the sigmoid, therectum, 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 andelectrolyte 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 andCampylobacter. 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 andlymphocytic 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.

Colitis Symptoms

Symptoms of colitis will depend upon the type of colitis that is present, but in general, colitis most often is associated with abdominal pain and diarrhea.

Other symptoms may inlcude:

• Blood in the bowel movement may or may not be present. 
  
  
• Tenesmus may exist; this is the constant urge to have a bowel movement. 
  
  
• The abdominal pain may come in waves, building to diarrhea, and then waning. 
  
  
• There may be constant pain.
  
  
• Fever, chills, and other signs of infection and inflammation may be present depending upon the cause of colitis.

Colitis Treatment

Self-Care at Home

If a person has bloody diarrhea, fever or intense pain, it is reasonable and appropriate to seek medical help by calling a health care practitioner or seeking care at a hospital emergency department.

Medical Treatment

The definitive treatment of colitis is dependent upon the cause. Many cases require little more than symptomatic care, including clear fluids to rest the bowel and medications to control pain. Some patients become acutely ill and will need intravenous fluids and other interventions to treat their illness.

• Infections: Infections that cause diarrhea and colitis may or may not require antibiotics, depending upon the cause. Viral infections resolve with the supportive care of fluids and time. Some bacterial infections like Salmonella also do not need antibiotic therapy; the body is able to get rid of the infection on its own. Other bacterial infections like Clostridium difficilealways require treatment with antibiotics.
  
  
• IBD: The inflammatory bowel diseases (IBDs), ulcerative colitis and Crohn's disease, are often controlled by a combination of medications that are used in a step-wise approach. Initially, anti-inflammatory medications are used, and if these are less than successful, medications that suppress the immune system can be added. In the most severe cases, surgery may be required to remove all or parts of the colon and small intestine.
  
  
• Ischemic colitis: Treatment for ischemic colitis is initially supportive, using intravenous fluids to rest the bowel and prevent dehydration. If adequate blood supply to the bowel isn't restored, surgery may be required to remove parts of the bowel that have lost blood supply.
  
  
• Diarrhea and abdominal pain: Most causes of colitis present with diarrhea and crampy abdominal pain. These symptoms are also found with mild illnesses like viral enteritis (inflammation of the colon). Initial treatment at home may include a clear fluid diet for 24 hours, rest, and acetaminophen (Tylenol) as needed for pain. Often symptoms resolve quickly and no further care is needed.

Surgery

Surgery may be required for ischemic colitis, Crohn's disease, or ulcerative colitis, depending upon the severity of the illness and its response to more conservative non-surgical treatments.

In ulcerative colitis, removal of the colon cures the disease.

For other illnesses, usually the part of the colon that is at risk or damaged is removed.

Prevention

Infectious colitis remains a common ailment worldwide, affecting millions daily. The lack of clean drinking water and adequate sanitation are the main causes, leading to thousands of potentially preventable deaths each day. In developed countries, poor hand washing and poor kitchen hygiene allow the potential for infectious colitis. Prevention lies in cleanliness.

Inflammatory bowel diseases may be difficult to prevent at the present time. The likely causes are heredity and perhaps an abnormal auto-immune response to an unknown stimulus in the body.

Since ischemic colitis is caused by narrowing of the blood vessels to the bowel, decreasing the risks for other types of circulatory problems such as peripheral vascular disease, heart attack, and stroke will also decrease the risk for ischemic colitis. The common risk factors are smoking and poor control of high blood pressure, high cholesterol levels, and diabetes.