The appendix is a small, tube-like organ attached to the first part of the large intestine, also called the colon. It is located in the lower right area of the abdomen. It has no known function. A blockage inside of the appendix causes appendicitis. The blockage leads to increased pressure, problems with blood flow and inflammation. If the blockage is not treated, the appendix can break open and leak infection into the body. Symptoms may include Pain and/or swelling in the abdomen Loss of appetite Nausea and vomiting Constipation or diarrhea Inability to pass gas Low fever Not everyone with appendicitis has all these symptoms. Appendicitis is a medical emergency. Treatment almost always involves removing the appendix. Anyone can get appendicitis. It happens most often to people between the ages of 10 and 30.