6 common causes of colitis
Inflammation of the colon can be caused by a variety of illnesses and
infections. Some of the most common causes are discussed in the next few
1. Infectious Colitis
Viruses and bacteria can cause colon infections. Most are food-borne illnesses or "food poisoning." Common bacterial causes
of food borne infection include
Shigella, E Coli,
Campylobacter. These infections may cause
bloody diarrhea and can result in significant
- Parasite infections such as giardia also 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 also
may be contaminated water from a well or cistern.
Pseudomembranous colitis is caused by the
Clostridium difficile (C. difficile). This disorder is often seen in patients who have recently been taking
antibiotics for an infection
or have been admitted to the hospital. The antibiotic alters the normal bacteria present in the colon
that helps with digestion and allows an overgrowth of the
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.
2. 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 lose 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
- Ischemia or lack of blood supply causes significant pain, fever, and bloody bowel movements.
- Blood clots can also travel or embolize to block an artery and decrease blood flow to the bowel.
Individuals who have the common heart rhythm disturbance, atrial fibrillation, are at risk of forming small clots in the heart, which break off and block the blood supply to the bowel. This is the same mechanism that can cause a stroke or TIA (transient ischemic attack) if the blockage occurs in an artery that supplies the brain.
Medically Reviewed by a Doctor on 6/20/2016
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