What is appendicitis and what causes appendicitis?
Appendicitis means inflammation of the appendix. It is thought that appendicitis
begins when the opening from the appendix into the cecum becomes blocked. The
blockage may be due to a build-up of thick mucus within the appendix or to stool that
enters the appendix from the cecum. The mucus or stool hardens, becomes
rock-like, and blocks the opening. This rock is called a fecalith (literally, a
rock of stool). At other times, it might be that the lymphatic tissue in
the appendix
swells and blocks the opening. After the blockage occurs, bacteria which normally are found within the appendix begin
to invade (infect) the wall of the appendix. The body responds to the invasion by
mounting an attack on the bacteria, an attack called inflammation. An alternative
theory for the cause of appendicitis is an initial rupture of the appendix
followed by spread of bacteria outside of the appendix. The cause of such a
rupture is unclear, but it may relate to changes that occur in the lymphatic tissue,
for example, inflammation, that lines the wall of the appendix.)
If the inflammation and infection spread through the wall of the appendix,
the appendix can rupture. After rupture, infection can spread throughout the
abdomen; however, it usually is
confined to a small area surrounding the appendix (forming a peri-appendiceal
abscess).
Sometimes, the body is successful in containing
("healing") the appendicitis without surgical treatment if the infection and
accompanying inflammation do not spread throughout the abdomen. The
inflammation, pain and symptoms may disappear. This is particularly true in
elderly patients and when antibiotics are used. The patients then may come to
the doctor long after the
episode of appendicitis with a lump or a mass in the right lower abdomen that is
due to the scarring that occurs during healing. This lump might raise the
suspicion of cancer.