MODEL RELEASED. Test for appendicitis. A doctor uses his fingers to feel the lower abdomen of a young boy lying on a bed. This technique, called palpation, enables him to feel whether the appen- dix is inflamed, indicating appendicitis. Appendi- citis is the acute inflammation of the appendix, a small finger-shaped branch of the large intestine. The condition is common in children and young ad- ults, and often occurs without a known cause. If untreated the inflamed appendix can burst, causing infection of the lining of the abdomen (peritoni- tis). The usual treatment for appendicitis is surgery to remove the diseased appendix (appendicectomy).