DIVERTICULITIS - Inflammation of a colonic diverticulum. Most common in those after age 50, diverticulitis has been referred to as "left-sided appendicitis." Common symptoms include left, lower quadrant abdominal pain, nausea, vomiting, and fever. Treatment of mild cases can be accomplished with a clear liquid diet and oral antibiotics. Complications include intestinal perforation and gastrointestinal bleeding (rectal bleeding).