What condition involves inflammation or infection of the appendix?

The condition that involves inflammation or infection of the appendix is appendicitis. This medical situation arises when the appendix, a small, tube-like structure attached to the large intestine, becomes inflamed, often due to an obstruction that leads to bacterial infection.

Symptoms of appendicitis can include abdominal pain, particularly in the lower right quadrant, nausea, vomiting, and fever. It's a common condition that typically requires surgical intervention, often in the form of an appendectomy, to prevent complications such as a ruptured appendix, which can lead to peritonitis or sepsis.

The other conditions mentioned—cholecystitis, diverticulitis, and colitis—are related to different parts of the digestive system and involve distinct etiologies and pathophysiological processes. Cholecystitis refers to the inflammation of the gallbladder, diverticulitis involves inflammation of diverticula in the colon, and colitis indicates inflammation of the colon. Each of these conditions exhibits its own unique symptoms and treatment approaches, further distinguishing them from appendicitis, which specifically pertains to the appendix's inflammation or infection.