Colitis is inflammation of the colon. In the colon, diverticula may exist, a sort of minor swelling of the mucus membrane, which can become inflamed, triggering diverticulitis. This localized inflammation of the colon generates pain in the lower left part of the abdomen and a fever. Colitis itself is a chronic inflammation of the colon, mainly represented by two closely related diseases: Crohn's disease and ulcerative colitis. The clinical signs are quite similar: diarrhea, abdominal pain, and bleeding from the anus. The endoscopic examination of the colon is necessary to differentiate the two diagnoses and implement treatments. These are also closely related and involve corticosteroids, immunosuppressants, or surgery.