While both colitis and ulcerative colitis involve inflammation of the colon, they affect your health and comfort in different ways. Colitis is a broad term that refers to any inflammation of the colon, which can be triggered by infections, ischemia, reactions to medications, or allergies, typically presenting with abdominal pain and diarrhea. Ulcerative colitis, a subset of colitis, is classified as an inflammatory bowel disease and is marked by long-term inflammation and ulcers on the colon's inner lining, often resulting in more intense symptoms.