Dr. Wise Guy on Instagram: "What is Appendicitis? Appendicitis is a painful medical condition that occurs when the appendix—a small, finger-shaped pouch attached to the large intestine—becomes inflamed and infected. This usually happens when the appendix is blocked by stool, mucus, or other debris, allowing bacteria to multiply rapidly. The result is swelling, increased pressure, and a buildup of pus, which can cause severe abdominal pain, typically in the lower right side. If left untreated, th