Partly digested food and liquids traveling through the bowel pass in and out of the pouch when it is open. If this flow is blocked, bacteria trapped in the appendix may multiply. This is thought to cause appendicitis. The pain grows worse with time, causing nausea and vomiting. When this occurs, there is often relief of the pain for a short while, 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. Appendicitis occurs when bowel contents that flow into the appendix are blocked and cannot flow out. Normal intestinal bacteria get trapped and multiply, causing swelling and infection. 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 benign tumor called a carcinoid.