Appendicitis is an infection of a small pouch off the bowel called the appendix.
The appendix is a pouch that branches off the large bowel near where the small and large bowel join together. It is about the size of a person's little finger.
The appendix is lined with a mucous membrane that produces a clear secretion. This organ has no known function, though it is possible 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, causing the inflammation we know as appendicitis.
Appendicitis often starts with mild pain near the navel, sometimes accompanied by nausea, vomiting, diarrhea, and loss of appetite. The pain gradually moves to the right lower part of the abdomen. It worsens with time, and is more intense when the person moves. At this stage, the person may have a fever.
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 unusual. It causes a milder pain in the right lower abdomen that may come and go.
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.
Appendicitis cannot be prevented.
The diagnosis of appendicitis can be strongly suspected from a history of gastrointestinal discomfort which has progressed over a period of hours to pain in the right lower abdomen, though the exact symptom sequence and location of pain can vary. On physical exam, the person usually looks very uncomfortable and tries to avoid movement. The abdomen is tender at the spot of the pain.
A higher-than-normal white blood cell count, with more immature white cells than normal on the blood smear, together with an elevated temperature, help to confirm the diagnosis.
Often, the healthcare professional will order an abdominal CT scan or ultrasound. Sometimes it is necessary to open the abdomen surgically without a definite diagnosis beforehand.
Most commonly, an inflamed appendix, if not treated, will rupture, leading to peritonitis, which is an infection in the abdominal lining.
While it is possible to get over an attack of appendicitis without having surgery, this is not a reasonable risk for a clinician to take. Even if the person does not suffer a rupture, he or she may later experience episodes of chronic appendicitis or bowel blockages.
Appendicitis is not contagious, and poses no risks to others.
Surgery to remove the appendix is called an appendectomy. If the appendix has not ruptured, an appendectomy is a relatively simple operation carried out through a small incision in the right lower abdomen. Antibiotics may be given before or during the operation to prevent or treat infection.
A ruptured appendix requires more extensive surgery to clean infected material out of the abdomen. As many as one in five people with appendicitis end up with an abdominal abscess, a pus pocket that must be drained surgically.
Surgery can be complicated by bleeding, infection, or an allergic reaction to the anesthetic.
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.
Any new or worsening symptoms should be reported to the healthcare professional.