Diseases & Conditions

Appendicitis


Overview, Causes, & Risk Factors

Appendicitis is an infection of a small section of the bowel called the appendix.

What is going on in the body?

The appendix is a pouch at the junction of the small and large intestines. It is the size of a small finger. The pouch is lined with a mucous membrane that produces a clear secretion. This organ has no known function. One theory, though, is that it plays a role in the immune system very early in life.

Partly digested food and liquids traveling through the bowel pass in and out of the pouch. If this flow is blocked, bacteria trapped in the appendix may multiply. This is thought to cause appendicitis.

What are the causes and risks of the infection?

Appendicitis occurs when bowel contents that flow into the appendix are blocked and cannot flow out. Normal intestinal bacteria get trapped and multiply. The appendix becomes swollen and infected. The blockage may be due to very thick bowel contents or another obstruction. While cancer of the appendix is very rare, the block is occasionally due to a noncancerous tumor called a carcinoid.


Symptoms & Signs

What are the signs and symptoms of the infection?

Appendicitis often starts with mild pain near the navel. The pain gradually moves to the right lower part of the abdomen. It worsens with time, and is more intense when the person moves. Other symptoms of appendicitis may include:

  • diarrhea
  • fever in the later stages of appendicitis
  • loss of appetite
  • If the infection continues, the appendix may rupture. When this occurs, there is often relief of the pain for a short while. This improvement is followed by more intense but similar pain.

    Chronic appendicitis is rare. It causes a milder pain in the right lower abdomen that may come and go.


    Diagnosis & Tests

    How is the infection diagnosed?

    Diagnosis of appendicitis begins with a history and physical exam. A healthcare provider will order blood tests. People with appendicitis usually have a higher-than-normal white blood cell count. The cells may look immature, too. Occasionally, the provider will order an abdominal CT scan or ultrasound. Sometimes exploratory surgery must be done.


    Prevention & Expectations

    What can be done to prevent the infection?

    Appendicitis cannot be prevented.

    What are the long-term effects of the infection?

    Untreated appendicitis may lead to peritonitis, which is an infection in the abdominal lining. Untreated appendicitis may also lead to a ruptured appendix. Some people get over an attack of appendicitis without having surgery. However, they may later have episodes of chronic appendicitis or bowel blockages.

    What are the risks to others?

    Appendicitis is not contagious, and poses no risks to others.


    Treatment & Monitoring

    What are the treatments for the infection?

    Surgery to remove the appendix is called an appendectomy. Antibiotics may be given to prevent or treat infection. A ruptured appendix may require more extensive surgery. As many as one in five people with appendicitis end up with an abdominal abscess, or pus pocket.

    What are the side effects of the treatments?

    Surgery can cause bleeding, infection, or allergic reaction to anesthesia.

    What happens after treatment for the infection?

    After surgery for uncomplicated appendicitis, most people are discharged from the hospital in 24 to 36 hours. They can usually return to normal activities in less than two weeks.

    How is the infection monitored?

    Any new or worsening symptoms should be reported to the healthcare provider.


    Attribution

    Author:Michael Peetz, MD
    Date Written:
    Editor:Crist, Gayle P., MS, BA
    Edit Date:06/01/01
    Reviewer:William M. Boggs, MD
    Date Reviewed:06/01/01